Newly engaged Mary-Kate Olsen turned down fiance Olivier Sarkozy's first proposal, Us Weekly can exclusively reveal; the couple are also already talking about having children together Credit: James Devaney/

She took her time! Mark-Kate Olsen made sure fiance Olivier Sarkozy was the one before saying "yes" to an engagement. An insider reveals exclusively in the new issue of Us Weekly that Sarkozy first proposed months ago, but the fashion designer turned him down at the time.

"He tried about a year ago, and she wasn't ready," an insider tells Us in the March 17 issue's Hot Stuff. "She didn't need to be wined and dined. She wanted to make sure he would be good to her."

Olsen, 27, and the French banker, 44, first went public with their relationship in 2012, and are also "talking about trying to get pregnant," the source says.

Us exclusively broke news on Feb. 28 that Olsen and her older beau are engaged. "Mary-Kate's family thinks Olivier is the best thing to happen to her," an insider told Us of the former Full House star. "They love him."

Olsen won't have a hard time adjusting to motherhood, either. She's already close to Sarkozy's two children Julien, 12, and Margo, 10, from his previous marriage to Charlotte Bernard.

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

Olsen has yet to confirm the engagement news herself, but has already shown off her new rock. The actress stepped out wearing her huge gold engagement ring in NYC on March 3.