Actress Mary-Kate Olsen

Mary-Kate Olsen is engaged to Oliver Sarkosy.

The former child star is set to marry her partner of two years - who is the half-brother of former French president Nicolas Sarkosy - according to

Their marriage will be Mary-Kate's first and Oliver's second, after he was previously wed to Charlotte Bernard, with whom he has two children, Julien, 12, and Margo, 10.

A source has claimed they are a good match, saying: "Mary-Kate's family thinks Olivier is the best thing to happen to her. They love him.

"Mary-Kate has made him a better father. She remembers all the kids' special events. She thinks he's a great dad."

The actress-turned-designer and the banker first started dating in 2012 and live in New York where they have a $6.25 million townhouse.

Speaking about her relationship, Mary-Kate told the Wall Street Journal newspaper: "Everyone has an opinion. I find it's better to focus on what's in front of you and to keep putting one foot in front of the other."

Mary-Kate's twin sister, Ashley, is also dating an older man, with it recently confirmed she is seeing 47-year-old 'Moneyball' director Bennett Miller.