The 30-year-old actress-turned-fashion designer also opens up about her marriage to French banker Olivier Sarkozy and her two stepchildren, Julien, 15, and Margot, 13, reported Femalefirst.
"I've always been a worker. It has taken me a lot to figure out how to take a vacation. I think we're lucky (working hard) comes quite naturally for us. We don't need so much time to sit and think and ponder, Mary-Kate says.
"But then I have a husband, two step-kids 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," she adds.