Mary-Kate and Olivier married in 2015 in a private New York ceremony.
Though the fashion designer rarely speaks to the press about her personal life, in 2017 she spoke to Net-A-Porter's The Edit about her marriage.
“We’re lucky [working hard] comes quite naturally for us. We don’t need so much time to sit and think and ponder,” she told the publication.
“But then I have a husband, two stepkids and a life; I have to go home and cook dinner. I ride horses on the weekends.
“You find the thing that helps you relax and if you don’t have it, you have to look for it. Or you get burned out and then you’re not productive.”
Olivier Sarkozy, is former French President Nicolas Sarkozy's half-brother, whilst Mary-Kate is one half of the Olsen twins with sister Ashley.
The two rose to fame as child stars and even booked their first audition at the young age of six months.
But in a recent interview with Marie Claire, Mary-Kate referred to herself and her twin sister as "little monkey performers."
“I look at old photos of me, and I don’t feel connected to them at all … I would never wish my upbringing on anyone,” she told the publication.
In 2004, Mary-Kate checked herself into rehab for an eating disorder and an alleged drug addiction.
Three years later when she was 21 years old, the former child star also suffered from kidney problems, but has since made her mental and physical health a priority.
"I think it’s really important to be able to talk when something’s wrong. I learned at a really young age that if you don’t talk about it, it can drive you insane,” she told Marie Claire.