Actress Leven Rambin, best known for her role as Sloan, Mark Sloan’s daughter in Grey’s Anatomy, is engaged to film producer Geoff Clark after dating for just six months. Geoff Clark proposed to Leven Rambin while walking along a beach in the Bahamas over New Year’s. But was Clark moving too fast?

No way, according to the 19-year-old actress, who met her fiancé through their mutual friend, celeb photographer Tyler Shields.

"Little did Geoff know that I was praying for him to propose," Rambin tells PEOPLE. "I knew I wanted it to happen."

Clark, 28, says Rambin is "extremely happy" and "almost like a whole new person," since getting engaged.

He acknowledges that in the past, when Rambin lived in New York City filming All My Children, local gossip columns depicted her as a party girl, but he says she’s changed.

"She used to be a wild child of sorts, but she’s definitely settled down," he tells PEOPLE. "I don’t want to say it’s because of me, but I think having some sort of faith in God, as opposed to having to rely on herself helped."

Rambin also laughs off criticism that at 19 she’s too young to get married. "I don’t think I’m too young. I’ve had a very full life," she says. "As a Christian, I think it’s really important to find a man of God to trust and be supportive of me. I’ve never met anyone like Geoff."

Rambin helped design her engagement ring with Kendra Bridel Weinman of the custom-made jewelry line Lusciouss. "I really wanted something that looked ‘antiquey’ and unique," she says of the sparkler, which consists of a pink tourmaline stone, floral detailing, and a platinum band. "It’s very feminine and very me."

Rambin and Clark haven’t set a date for their nuptials, but she has a location in mind. "I’d love to have the wedding in the Bahamas where we got engaged. It’ll always be close to my heart," says Rambin, who counts socialite Lydia Hearst among her BFFs.

As for the timing of the wedding, "We’ll probably do it either the end of this year or next summer," says Rambin. "I would marry him tomorrow in an elopement, but I really want it to be a proper ceremony. I’m not a really good organized bride-to-be. I’m definitely not a bridezilla!"