05/15/2009 AT 07:00 AM EDT
started her career as a model – and, following in her footsteps, her 4-month-old daughters have now posed for their first fashion photo
Featured with her girls for an InStyle
magazine spread, the actress says that Mom is her most rewarding role to date.
"Being a mom makes me feel whole and like I understand the meaning of life," Romijn, 36, tells InStyle
for the June Sexy issue, on newsstands May 22. "All I want to do is stare into my babies' eyes nonstop."
Romijn, who has already lost 60 lbs.
since giving birth
to Dolly Rebecca Rose and Charlie Tamara Tulip in December, is nearly back to her pre-baby body – but says she doesn't worry too much about her figure.
"I'm a jeans size up from where I usually am, but there's nothing about it that freaks me out," she says. "I feel as sexy as I have ever felt. I've always said that sexy is having a really strong sense of yourself and never taking yourself too seriously."
As for how her husband, Jerry O'Connell, is handling a house full of women, Romijn praises him as a wonderful dad. "He's got endless amounts of energy, and he's having such a blast with these girls."
Just don't ask O'Connell what it will be like when the girls are older. Jokes Romijn: "He's determined not to let them ever date while he is alive."