She entered law school in 1981, was admitted to the bar in 1985 and was made partner at leading Auckland law firm Nicholson Gribbin in 1988. She was 25 - one of the youngest partners in the firm's then-117 year history, and the first woman.
When I mentioned this fact to Dr David Williams, who was one of her first law lecturers at the University of Auckland, he had to check he hadn't heard wrong: "25, did you say?"
"Yes," I said.
"God," he said.
To be made a partner at a major law firm at that age would be a remarkable thing even today. For a woman in the 1980s, it was unheard of.
At the time he taught Winkelmann, in 1981, Williams was president of Citizens Association for Racial Equality (CARE), which played a major role in protests against the Springbok tour. He was arrested several times during the tour and later claimed to have been on the field with the Springboks more than any other New Zealander who wasn't an All Black.
During one tour match he ran on to the field and yelled at the Springboks "Go home" in Afrikaans, Māori and English before being tackled by police. At the third test at Eden Park, he disguised himself to get into the ground and threw a smoke canister on the field. "At that point," he said in a speech years later, "you must get yourself arrested to avoid getting beaten up."
His first contribution to Winkelmann's education was a class called The Legal System, which Winkelmann remembers him coming to teach with his head bandaged, following a clash with the police Red Squad.
He said she later told him, "If it wasn't for some sense that law had something to do with justice and social justice she might not have continued with it … She had the strong sense that quite a few of the people in the room were not the sort of people that she necessarily agreed with a lot on a whole range of political and social issues, but at least she had a lecturer who thought that law and justice and social justice were important."
I said to Williams: "You'd think the two go together - the law and justice."
He said: "Ah, you might think so, except that lawyers spend a lot of time minimising tax and all those sorts of things that don't necessarily lead to equal outcomes for citizens. Yeah, no, there's lots of ways in which law and justice are a bit apart. The ideal of course is that law should strive for justice, but I think if you had me as your lecturer you would get the idea that there are some blemishes along the way, which I think is one of the things that Helen picked up."
As a student, Winkelmann took part in a lot of marches. There were plenty to choose from in the early 1980s. She protested education cuts and the university's engineering students and, obviously, the Springbok tour. For some of the protests, she went with her mother.
Winkelmann grew up in poverty. When she was at primary school, her parents couldn't afford to buy her stationery, so she would sit at her desk for three weeks at the start of each year waiting for a government grant to come through. On school trip days she would be forced to stay home.
"You had a pretty good sense that you were different," she says. "And I had a sense, because I've always been quite an observant person, I had a sense of feelings of shame."
Her father had fought in the Korean War. After returning home, he was diagnosed with multiple sclerosis (MS). With him confined to a wheelchair, unable to work, needing a large amount of care, eventually including feeding, the family's earning potential was ravaged.
When it was discovered he'd had symptoms of MS prior to the war, Winkelmann's mother fought for him to get a war pension, because stress is known to make MS worse and war is a well-known stressor.
Winkelmann says her mother modelled self-reliance and had a very strong sense of fairness and of social justice. She got on and fixed things herself. These are things that had a big effect on her daughter.
Her mother had to work hard for the war pension but when it came it lifted the family out of poverty and it changed their lives. Winkelmann has never been poor again, but she has also never forgotten what it was like: "Poverty is a very particular experience," she says, "And if you actually haven't experienced it you really can't understand the implications."
Her strongest message in the media campaign that has followed her appointment as Chief Justice has been about ensuring access to justice for all, not just for the rich and powerful: "I think it's important that those who have power never lose sight of what it is - was - like when you had no power. I think I had a pretty good perspective on that."
Although she was the youngest in her family, she says she was more like a classic oldest child. She calls herself "the goody two shoes", "the very good one", "the grown-up in the family". "That was my role," she says.
Her sister, fashion designer Adrienne Winkelmann, told Judy Bailey in a 2017 interview for Woman's Weekly: "Helen was the organiser ... We all used to joke that Helen was adopted because she was 'Miss Perfect' and the rest of us were tearaways."
At primary school, Helen wasn't convinced she was smart. That started to change, she says, when her teacher in year 9, third form, effectively told her she was. She went to that teacher's funeral earlier this year.
"Education is so important," she says now. "It's just hugely powerful."
I ask her how much of that is luck: "What happens if you don't end up with teachers like that one? Do you think about that?"
She says: "I do think about it, yeah."
I ask: "Do you think things could have been different?"
"I think they could have been different," she says. "Yeah, I really think they could have been different."
She had gone to law school straight from sixth form, year 12, at Lynfield College, because she was "impatient and over it really". She had wanted to study medicine but because she hadn't finished high school she thought she'd better do something easier.
She didn't fall in love with law right away - she was initially much more interested in history - but it grew on her. "I think it's something that the more you know, the more it captures you."
In a 2015 speech she said, "My memory of myself as a law student is that I was rather clueless," which is a faulty memory because she won the prize for best graduate. Nevertheless, when she graduated she still had the nagging thought that maybe she should have been a doctor. Asked now if she regrets not going to medical school, she says, "No, I don't regret it. That would be a futile thing to be doing."
By the time she made partner at Nicholson Gribbin in 1988, the number of women lawyers was growing but the number of women partners at Auckland law firms was so small they could fit around a small table, which they regularly did, at a cafe called Belinda's in Durham Lane.
One of the most important people in that group was Helen Melrose, one of the country's first woman partners and at that time the only woman partner at Chapman Tripp. Melrose says she felt like she was having to stand up in the face of an industry that wasn't especially welcoming for women, although she says she wouldn't necessarily attribute that same thought to Winkelmann, who she describes as bright, well organised and able to get along with people. "You had to be able to fit in," she says of those days.
Winkelmann, now 56, says: "I turned up looking like a child, I suppose. She was extremely welcoming and we would talk about issues. So I found out about maternity leave, what was the going thing. I had my first son when I was 26, so that became quite important quite quickly."
Two decades before Winkelmann started at the University of Auckland law school, it had been hard to find a woman at the country's law schools. By the time she started, in the early 1980s, there were nearly as many women as men. Today, at the University of Auckland, nearly two-thirds of law students are women. Last year, the profession for the first time employed more women than men.
What's in a number? The revelation in February last year of sexual harassment allegations at Russell McVeagh blew up to headline-level the issues facing women in the law, but in the months following there was a steady flow of stories about broader issues of sexism and gender discrimination in the profession.
Late last year, in the New Zealand Women's Law Journal, University of Auckland law lecturer Anna Hood wrote an essay titled: "Reflections on the Perpetual Cycle of Discrimination, Harassment and Assault Suffered by New Zealand's Women Lawyers and How to Break it After 122 Years."
In it, she wrote: "[We] have become trapped in a cycle whereby discrimination occurs, concerns are raised, the raising of concerns lulls people into a false sense of believing that change is happening, the structural problems that give rise to discrimination are left untouched and it is only a matter of time until discrimination rears its head again."
She wrote that there's still a belief women are not suited to "serious" commercial aspects of legal practice and that women are being screened out of jobs through problematic interview questions.
"While I have not heard stories of women being asked about their approach to or choice of contraception in job interviews, female students discuss the fact that they still, at times, get asked about their marital status in interviews." In an interview for a graduate position at a top Auckland firm in 2006, Hood herself was asked whether she liked baking muffins.
Women still make up only a little over 30 per cent of partners in law firms and - over a six-year period to 2017 - made up less than 30 per cent of lead counsel in the Court of Appeal.
A 2014 AUT study which found women were leaving large law firms in disproportionate numbers discovered some recurring reasons why, including the masculine culture, burnout, a male-dominated environment and women's responsibilities for children.
Winkelmann had four children while working for her first employer, her first coming the year after she was made partner. The firm was, she says, progressive, with a good ethos and male partners who were extremely encouraging and supportive, but still, she says, "Having children does have an impact on your career, especially when you're the primary caregiver. And I think most women still are the primary caregiver. That might be a model we need to think about. But that's really for women. And men."
She put her career plans on hold once she started having children. "It's a very all-consuming thing," she says.
"It makes you far more vulnerable I think. It gives you a perspective that you did not have before. It gives you a perspective about what parents are trying to do. You understand things about your own parents you didn't understand. Man, do you understand things about your own parents you didn't understand!"
She became a High Court Judge in 2004, Chief High Court Judge in 2010 and was appointed to the Court of Appeal in 2015. Her profile grew along with her involvement in high-profile cases. While at the High Court, for instance, she was heavily involved in both the Kim Dotcom case and the Urewera "terror raids" case.
In 2012, she told RNZ's Kathryn Ryan that she tells new judges it's only a matter of time before they become involved in something controversial. "It's quite an awesome responsibility to be a judge," she said. "And I suppose I burst their bubble a bit by telling them about the fact that in fact you're going to - it's going to get pretty real pretty soon, and to warn their families."
The Supreme Court is the country's final court of appeal but if you know less about it than you do about its US equivalent - and you probably do - the main reason is that in 1803 the US Supreme Court gave itself the power to strike down legislation, making it tremendously politically important and powerful. Our Supreme Court does not have that power.
US Justices also go through publicly televised confirmation hearings, in which they're questioned extensively by members of the Senate. The process that culminated in the appointment of Justice Winkelmann began with the Solicitor-General consulting existing Chief Justice Dame Sian Elias, retired senior court judges, the New Zealand Law Society, the New Zealand Bar Association and the Māori Law Society. The Solicitor-General then created a panel comprising retired former Governor-General Dame Silvia Cartwright and retired Supreme Court Judge Sir Terence Arnold. That panel considered the consultation feedback and passed its advice to the Prime Minister, who made the final recommendation. None of these proceedings are made public. Winkelmann wouldn't even say who called her to tell her she had the job.
The judiciary is one of New Zealand's three branches of Government - the other two are Parliament and Cabinet. As head of the judiciary, the Chief Justice is one of the most powerful people in the country. We are used to associating power with grand ambitions, grand plans, plays for influence and attention, but here are the things Winkelmann wants to be remembered for.
"That I improved access to justice; that I supported an improvement in access to justice; that I led a judiciary that had a clear sense they were here to serve the community; that I led courts that deal with all who come before them in a way which affords all of those people a full measure of human dignity; that I led courts that had a good sense that the law must be certain and clear and that the law must reflect our particular traditions and history and serve our particular social needs.
"It's not our task to make radical change in our society, she says. "That's for Parliament."
She says: "I'm not a revolutionary. I believe in the law and I believe in working within the law."
She says, of Supreme Court Justices: "We're not up there being a bunch of individuals just doing what we like. I'm a guardian of some important principles in the law."
If this all sounds quite boring, and it does, that's not to say Winkelmann can't and won't make a difference, or that she doesn't want to. Change will come, she says, and needs to. She wants a more diverse group of judges, for instance. She wants greater connection with community, greater clarity and greater certainty around law.
These things are important, no doubt, but they make for terrible headlines. It's hard to imagine a Prime Minister - Winkelmann's equivalent in the Government's executive branch - offering an interviewer a vision of a legacy so devoid of media-friendly, big-ticket achievements.
Maybe it's helpful to think of this in metaphors. The Chief Justice is less like a thrower of smoke bombs and more like a parent. Her job is not to change the country but to make sure everyone gets a fair shot. Another way to think about it: the most important people in the country are not necessarily the ones getting all the attention.