Not so long ago, she wasn't sure if she loved or hated the game, but now she is World Rugby's player of the year for the discipline
and an Olympic champion -- and one half of Australia's sporting golden couple.
"Both my older brothers played it and I'd never played it until I was 16 or 17, and I was asked to play it after a touch footy game," she recalled ahead of the season-opening tournament in Dubai. "I was asked to take the game further and I went through a few different phases.
"Sometimes I loved it and then I'd go through a phase of thinking, 'This is not going to work out for me.' It was the contact side of things that I struggled to get my head around to start with. I'm glad I stuck with it."
Having danced around much of the opposition as Australia's playmaker in chief en route to winning Olympic gold
in August, one could argue that Caslick does not tend to find herself too much on the receiving end of the contact side of the game.
The 21-year-old and her teammates made a perfect start to the new campaign in Dubai Thursday, winning all three group games at a tournament they won last year on the way to claiming the 2015-16 Women's Sevens World Series
"The plan for me is to stay fit and healthy, and stay at the top of my game," Caslick says. "I like to think this is just beginning for us. New Zealand won the World Series back to back so we're looking to try to do that.
"Our coach instils in us that you can have one good tournament or even season, but it's the way you back that up that makes a great side, and that shows true character."
But what a year 2016 proved to be, with Australia peaking at just the right time to claim the first women's rugby gold to be awarded at an Olympics.
For Caslick, the medal rarely leaves her side -- although it now has a few bumps in it, having been swung around by a variety of children at the numerous school visits she has made since the Games.
Her success on the field has been in stark contrast to the struggles of her boyfriend Lewis Holland
, the new captain of Australia's men's sevens team.
While 2016 proved a career high for Caslick
, it has been a nadir for 23-year-old Holland.
He was sidelined for 10 weeks with an ankle injury before the Olympics, then a hamstring injury forced him out of the latter part of the tournament, and now he faces a far longer layoff after tearing the Achilles tendon in his right leg during training.
"I went from the best day of my life in Rio to the worst in the space of 48 hours," she recalls of their opposite fortunes in Brazil.
"But it just shows what sport is like, and you have to appreciate these things happen. And now it looks like he's going to miss the entire season. But it's a chance to get his body right and he's still very involved with the squad."
Australia seems to be in rapture to the golden couple of sevens post-Rio, and Caslick laughs at the nickname.
"It's quite funny," she says, "and we don't mind. It's just good fun really.
"But we try to keep our rugby life and our home life quite separate. We'll catch up at the end of the day about how it's gone but I guess we're much like any couple."
Australian sevens is turning into something of a family affair, with Charlotte's brother Sam Caslick set to make his World Series debut in Dubai, having been selected for the men's squad following a successful debut at last month's Oceania 7s in Fiji.
Since Rio, Caslick's life has been a whirlwind ranging from the many awards both for her and the team, to all manner of invitations.
That she has got to this point in such a short period of time might seem surreal to many, but not the player herself.
"I grew up wanting to be the best in the world in whatever sport," she says, having been a budding 800-meter runner and field hockey player. "I've had a dream run and it's so special for all of this to come so early in my career.
"The last two and a half years have been a blur from leaving home for the first time. I feel lucky to have found rugby and traveled the world playing the game. But I want to stay on top."
From watching Michael Phelps' final swimming race to being asked at school visits if her medal is in fact made of chocolate, Caslick has relished helping to put rugby sevens on the map in Australia.
In Dubai this week, the aim is to keep it there.