Fox shied away from the sport for a time, perhaps due to her parents' involvement, preferring swimming and gymnastics. A broken arm in 2005, and a subsequent medical suggestion she take up kayaking to strengthen the arm, got her into it and she's never looked back.
"I've been very lucky in my sporting trajectory," Fox said. "To live in Penrith and have a whitewater course in my backyard, when I was 12, I had access to one of the best venues in the world. To make the Australian team at 16 meant I got valuable racing experience as well."
Younger sister Noemie won silver in the C1 team event at last year's worlds in Pau, enhancing that all-in-the-family feel about this story. So what's the appeal?
"I used to do swimming. What I loved about swimming was the head to head racing; what I hated about it was the repetitive nature of it. It got a bit dull.
"With kayaking and slalom, in particular white water rapids, every day was different. You could be training 10 years on the same course and still learn new things, new moves. It's the variety, the elements of expression and creativity and thinking outside the box - and the excitement and adrenalin of the rapids."
Study is on hold. Fox is doing an online degree, slowly, in social science and communication. She initially wanted to go into medicine, then qualified for the Olympics in 2012. "I thought 'oh well ..."
Canoeing is now her life, and a good one it is, too. Her best moments? Two stand out. Firstly, a World Cup win in Ivrea, Italy, last year, when Fox hit the first gate in the final, which meant a 2s penalty.
"I knew I had to really attack it and not make any mistakes from that point. It was probably one of the best runs I've had in the canoe category. I won by 10s."
Then the day after chasing a fourth successive C1 world title in Pau last year, only to have a "disastrous" race, she won the K1 crown. ''It was one of those runs where you're in the flow. Athletes talk about being in that zone."
Fox finished third at the 2016 Rio Olympics, one spot behind New Zealand's talented Luuka Jones. Fox is an admirer of the Bay of Plenty paddler.
"She is very good in C1, she's progressed so quickly and paddles very much like she does in K1. She's got a very risky style but she's very good at it. It'll be a really good race this weekend."
One athlete is allowed in each discipline per country in the Olympics. Women will contest the C1 category for the first time in Tokyo in 2020, as the International Olympic Committee moves to equalise the gender balance. Fox is keen to push on for Tokyo, and given her earliest years, Paris in 2024 has special appeal.
"I'm loving this stage of my life and career. I'm feeling like I still have a lot more to give."
Footnote: In C1 racing, the athlete kneels on both legs, with straps to prevent them sliding forward, and uses a single bladed paddle.
K1 athletes use a double bladed paddle while seated in the kayak.