Margot, of course, played Donna Freedman on the show, who was initially introduced as a guest star but eventually became a series regular. Her career then went on to flourish as the actress landed roles in The Wolf of Wall Street alongside Leonardo DiCaprio, I Tonya, Once Upon A Time In Hollywood and more.
Cameron previously spoke to TV Week about what it’s like to join the show where his sister got her start.
“It's a little surreal but maybe that's because it's been about a decade between us being on the show," Cameron told the publication.
"There are still some cast and crew who have worked with her and tell me stories and it's pretty lovely to see the impact she's made.
The actor also shared some tips that Margot gave him when he initially booked the role, explaining that the starlet told him to “work hard, train hard, be kind and grateful, and enjoy the experience,” before adding, “it’s always comforting to know that if I ever need her she's only a phone call away”.
Not only is she a phone call away, Margot has made it very clear that her heart belongs down under with her family. Back in 2016 during an interview with The Project Australia, the actress confirmed that, although she spends a lot of time in LA, she will be returning home when it's time to settle down.
Sitting with journalist Carrie Bickmore, her mother Sarie and older brother Lachlan at their family home in the Gold Coast, Margot was quick to correct her mum when she voiced concerns about not seeing her future grandkids as they may be overseas.
"No mum, they'll be here," Margot said definitively. "The kids will be in Australia."
But before Margot takes this next step, she has been busy exploring the world with Cameron himself.
A few years ago, the brother and sister backpacked across Croatia together, a trip which came to a rather chaotic end.
Speaking with Entertainment Weekly about her audition for the film Focus, which she starred in with A-lister Will Smith, Margot explained why she was forced to cut her overseas trip short.
“I was backpacking for a week with my brother on an island off Croatia. I end up having the craziest 24 hours of my life. I’m soaking wet because I’d been swimming, I get back to the hostel at 6am, no sleep, turn my phone on, and I’ve got all these messages: ‘They want you to audition for Focus. Your flight leaves tonight.'"
“I walk into the audition and it turns out Will was running late. He comes in and says, ‘Sorry I’m late, I was coming from Queens.’ And I look at Will and I was like, ‘Yeah? Well, I just came from an island off Croatia and I’m here on time.'”
Press junkets are familiar territory for Margot, who is constantly promoting her latest projects. And while interviews have a tendency to become repetitive and boring, there's nothing like a brotherly surprise to liven up a junket.
Back in 2018, when Margot was doing press for the film Peter Rabbit alongside The Crown's new Princess Diana Elizabeth Debicki, the actress was stunned when her little bro Cameron rocked up to conduct the interview.
"Oh my god," Margot exclaimed upon being surprised with her sibling.
"Excuse me, can you calm down? We’re in an interview," Cameron jokingly replied.
While the siblings engaged in some classic brother-sister back-and-forth, there was no denying the tears in their eyes as they reunited.
The pair also feature on each other's Instagrams from time-to-time.
In February last year, Cameron shared a heartwarming tribute to Margot that was equal parts sentimental and equal parts brotherly.
Posting a picture of him and his older sister at the BAFTAs (British Academy Film and Television Awards), Cameron wrote, "Funny world this one turned out to be. Incredibly amazed by you and your work. P.s - Sorry you lost. Twice. At the same time...👊 @boss P.p.s - me on the other hand, I’ve actually never lost a BAFTA... #justsayin."
It just proves that no matter how big you get, you can always rely on your siblings to humble you.