Welcome to the first wives club, Melania

Washington insiders can only speculate as to how Melania Trump will take to the momentous US First Lady role. Here she and President-elect Donald Trump arrive for a New Year's Eve party in Florida. Photo / AP

When Donald Trump is sworn in as the 45th President of the United States of America on January 20, the woman standing by his side will be thrust into the role of national and global figurehead, too; Melania Trump - his third wife, 24 years his junior, will become America's First Lady.

No other country demands quite the same level of responsibility of a presidential spouse, with the First Lady not only serving as ambassador, consort and hostess, but also occupying a position as the nation's idealised wife and mother.

As yet, Washington insiders can only speculate as to how Melania will take to such a momentous role. We've seen very little of her publicly since the election - sometimes it feels as if she's gone into hiding.

Symbolically, it is important for the First Lady to be at the White House, to show the public that she cares, but Melania will not even be based in Washington, at least for the first few months, remaining in New York instead so that their 10-year-old son, Barron, can finish the school year.

Ivanka Trump, meanwhile, has bought a house with her husband, Jared Kushner, in the capital, and indications are that she may take on the de facto role of First Lady.

This wouldn't be the first time in history the First Daughter has assumed such responsibilities - after Woodrow Wilson's wife died, and before he remarried, for a short time, their daughter filled in, and Martha Jefferson filled in for her mother, who died two decades before her husband was sworn in.

Melania (left) with Trump siblings Ivanka, Eric and Donald Jr during the second presidential debate between Donald Trump and Democratic presidential candidate Hillary Clinton. Photo / AP

But not in more than a century has it happened with a First Lady still living.

The weekend that Trump is inaugurated, Jackie will be released in UK cinemas, with Natalie Portman portraying the most iconic First Lady of all time, Jacqueline Kennedy.

Just 31 years old when her husband, John F Kennedy, was sworn in, she was 34 years old when he was assassinated. Yet, her legacy has outshone that of almost every other First Lady, in spite of holding the title for only two years and ten months.

That legacy is no accident. It was Jackie who coined the term "Camelot", to describe the Kennedy years in office, and it was she who created the legend and mythology surrounding them both.

Today, we take for granted that curation and presentation of image, but Jackie was incredibly ahead of her time.

For my latest book, First Women: The Grace and Power of America's Modern First Ladies, I interviewed several staffers who served in the Kennedy White House, who described to me Jackie's obsession with ensuring everything was perfect.

For her husband's funeral; she would call them at two or three o'clock in the morning asking about the most minute details.

The role of the First Lady is also that of Consoler-in-Chief - she is the person who comforts the nation in times of grief.

Laura Bush was an integral part of the administration after 9/11, visiting victims' families, and bringing the treatment of women in Afghanistan under the Taliban to public attention.

Laura Bush was an integral part of the administration after 9/11, visiting victims' families as Consoler-in-Chief during the term of former president George W Bush. Photo / AP

At a time when Jackie Kennedy, a 34-year-old widow, with two small children had every right to crumble into private grief, she had the strength to be there for the nation, too; to be the public figure the country needed.

She hadn't, however, always been such an enthusiastic First Lady.

She would often leave the capital on a Thursday night to travel to Virginia, where she would ride her horses, and not come back until Tuesday morning.

She also didn't want to do a lot of grunt work - duties that Lady Bird Johnson, the wife of the vice-president, excelled at.

According to her former social secretary, there were many times that a Girl Scout troupe would visit, and Jackie would simply not want to host them.

Natalie Portman as Jackie Kennedy in the film "Jackie." Photo / AP

Indeed, Jackie leant so heavily on Lady Bird to fill in for that the latter was known as "Saint Bird".

In most cases, the First Lady is also her husband's closest counsel, the keeper of state secrets - these women know exactly what is going on, which, of course, demands a high level of discretion, even within their marriage.

In the new film Jackie, when referring to JFK's numerous affairs, the First Lady says: "Women have sacrificed far more for far less," implying that it was a deal that she made.We saw that with the Clintons, too.

When I interviewed the maids and butlers who worked at the White House at the time, they all admitted that they knew about his affair with Monica Lewinsky - it had been going on for almost two years before the story broke.

It is unlikely that Hillary wasn't as fully aware.

Of course, Jackie's equal in recent years in grace and glamour has been Michelle Obama, who has also displayed great empathy and an ability to connect with the public, which has been very powerful in her husband's presidency.

Outgoing US First lady Michelle Obama smiles as she speaks at the 2017 School Counsellor of the Year ceremony in the East Room of the White House last week. Photo / AP

Determined to do things her own way, she too is a perfectionist, she went through more chiefs of staff than her predecessor, Laura Bush (Michelle had four in her eight years in the White House).

There was also a lot of tensions and fighting with the West Wing [ie the President's] staff in the first few months.

Obama's Chief Of Staff, Rahm Emmanuel, would want her to take part in events, and she would say: "There has to be a very good reason for me to be doing this, because I have to be here for my kids."

In spite of the public perception of Michelle as very modern, in many ways she's quite traditional, fashioning herself as "Mom-in-Chief", and championing campaigns such as childhood obesity and education for girls.

She chose not to take on something incendiary, like gun control.

Hillary Clinton, by contrast, was radical and trailblazing, seeing their administration as a true partnership; as Bill said when he took office, you were getting two for the price of one.

Hillary Clinton saw her First Lady role as a trailblazing partnership; as Bill said when he took office, you were getting two for the price of one. Photo / AP

Hillary, in a highly symbolic move, occupied an office in the West Wing (instead of the East Wing, where the First Lady traditionally has her office) and headed up healthcare reform.

She believed that there was more that could be done as First Lady, and that the role could be modernised.

However, the American public was not ready for it, and saw her as overstepping the mark, in part because she had not been elected. the American public still want to see, primarily, a devoted wife and mother; if a First Lady wants to influence policy, she needs to do it in private, with her husband.

Ironically, though, there is now a great groundswell of support for Michelle Obama to run for office in 2020.

Unfortunately, there is little chance of her doing so, according to her staff, who privately laugh at the very notion. She hates the deal-making, and the compromises on beliefs and principles that you are forced to make as a politician.

One of Michelle's greatest assets is her ability to be vulnerable publicly, something that has proved a problem for Hillary, as First Lady and particularly in her own presidential campaign.

It's also ironic that the attributes that we so admired and lauded Jackie Kennedy for - her strength, her poise, her discretion, standing by her husband - are the very things that Hillary has been so heavily criticised for.

Her stiff upper lip would likely have worked much better back in the 1950s and 1960s.

Had Hillary won the presidential election, I believe it would have changed the role of the presidential spouse; having Bill Clinton as First Gentleman would have challenged the gendered notion of a spouse sitting quietly by the president's side.

Who knows when that chance will come around again?

Kate Andersen Brower is a former White House correspondent for Bloomberg News and the author of First Women: The Grace and Power of America's Modern First Ladies, published by Harper Collins.