Rebecca Romijn may be famed for her beauty—after all, this is a woman who has graced the cover of Sports Illustrated’s swimsuit issue, not to mention countless Victoria’s Secret catalogs—but right now her body image is not the healthiest. “I can’t move anymore,” she says. “I’m a beached whale!”

Of course, this beaching is on doctor’s orders: The model turned actress is seven months pregnant with twin girls, and is marooned at her Calabasas, Calif., home on prescribed bed rest. On this sunny Thursday morning, she is hanging out at her Wagon Wheel Ranch—the 18-acre place she shares with her husband, actor Jerry O’Connell—alongside her two poodles, Better and Taco. Beside her bed is a teetering pile of 23 maternity books, from The Happiest Baby on the Block, which is somewhere in the middle, to Mothering Multiples, sitting right on top. Needless to say, she’s comfortably dressed for the occasion in a pair of Express sweats and a camisole top with a built-in support bra. “I have not been without a bra this entire pregnancy. I refuse,” she says, laughing uproariously. “I’m not taking any chances. I’m determined to keep the puppies up!”

Though the 36-year-old is into her third trimester (she’s due in January), she only recently bought her first maternity jeans. “Fashion is working in my favor for this pregnancy. All those Empire waists and tent dresses?” she asks, confounded. “And trapeze dresses? Honestly, when I was in New York working all summer, I would walk down the street thinking, ‘I’m so sorry that all these skinny girls have to walk around in maternity dresses!’ ”

All her life, Rebecca’s been one of those skinny girls. Born and raised in Berkeley, Calif., by a furniture-maker father and a teacher mom, she started modeling during her college years and became an immediate success, appreciated by both high-fashion women’s magazines and lusty men’s publications. When she began focusing on acting in the late ’90s (after guest spots on shows like Friends and a gig hosting MTV’s House of Style), she was determined to play characters as far as possible from her own history. “I have gone out of my way to avoid the cliché arm-candy roles,” she says. “I don’t even know how to do that.” Instead, she took on parts like that of a blue-skinned mutant in X-Men and a small-town cop in this month’s Lake City, a slow-moving Southern drama. “Of course [the producers] wanted the most ill-fitting uniform for me,” she says, laughing. “They got their wish! I had to check my vanity at the door.”

And while her recent high-profile TV role on Ugly Betty has her turning up the glamour with big hair and high heels, even that comes with a twist: Her character is a transsexual. (The part has been scaled back to a recurring schedule, which is perfect for the mom-to-be.)

Rebecca certainly didn’t mute the glamour for her first wedding, to actor John Stamos, back in 1998. The couple married at the Beverly Hills Hotel—four years after meeting at a fashion show—but split in April 2004 and there was speculation that the divorce had something to do with her not wanting a baby. Rebecca has an angry and emphatic response to that rumor: “There is absolutely no truth to that. That [story] was completely made up. I desperately wanted kids.” In fact, she says being pregnant is something she’s looked forward to her entire life. “I was never a girl who dreamed about what her wedding day would be like, but I’ve always dreamed about decorating my baby’s nursery.”

And now, finally, that dream is coming true. So, all kidding aside, how does the nearly 6-foot-tall stunner really feel about her new body? “I don’t think about my image. I’m not worried about my weight at all,” she says earnestly. “I’m making two people—I can’t eat enough. Sometimes I’m ravenously hungry.” And does she feel beautiful? “I do…” Rebecca pauses, as if perhaps not entirely convinced. “I feel beautiful. But I think Jerry knows that sometimes I feel beautiful these days, and sometimes I don’t.”

For his part, Jerry says, “I think Rebecca looks good, but sometimes…if we go out, um, maybe there’s a little bit of insecurity there—just a touch. I don’t think it’s founded or necessary, I mean, come on! Pregnant women are the most beautiful people ever.”

Rebecca met Jerry poolside at the Hard Rock Hotel in Las Vegas soon after splitting with John. She was in town filming a documentary about the fountains at the Bellagio Hotel, he was in town partying with old college friends, and their first date was a group outing to see the Blue Man Group. “Jerry was talking in my ear the entire show and cracking me up,” she says. “He talks a lot.”

The two married in July 2007 in a big hoedown-style wedding at their ranch. Guests included friends like singer Fergie, who also performed at the celebration, and Rebecca’s Ugly Betty castmates. More recently, her co-stars Vanessa Williams and America Ferrera threw Rebecca a baby shower in New York. America gave her a gift certificate for a foot massage because, Rebecca says, “My ankles were huge! I couldn’t see any bones in my feet.” And Vanessa, who has numerous friends with twins, showed Rebecca “the double-football hold” she’ll have to use to breast-feed her daughters. She’s also picked up a few mothering tips from good pal Angie Harmon, who already has two kids and is also pregnant right now.

With the recent influx of multi­ples in Hollywood (Angelina Jolie, Jennifer Lopez and Lisa Marie Presley have all given birth to twins this year), there has been a lot of buzz about who used medical intervention, like in vitro fertilization, to get pregnant. “We did not do IVF,” Rebecca says. “A year ago, we tried [the fertility drug] Clomid for a couple of months unsuccessfully. But by the second month, I was like, ‘Ahhh! I hate this!’ I think when you start messing with your own hormones, it’s crazy-making.” So, she stopped the Clomid, started appointments with a Chinese acupuncturist and took the conventional Grandma wisdom to heart. “I relaxed and I wasn’t stressed out, and sure enough—” she soon found herself pregnant.

Right now, she’s decided on a name for at least one daughter: Dolly. A lifelong fan of singer Dolly Parton, Rebecca recently met up with the star before a concert and told her she was considering the name for her baby. “She said, ‘I’ve never had children of my own, and I would just be so honored,’ ” the actress says in a near-perfect East Tennessee accent.

Rebecca and Jerry are also excited about another first for their family: Jerry planted 800 grapevines on their property three years ago, and they just hired a team to harvest their first bounty. By next year, the couple expects to have 120 bottles of Wagon Wheel Wine, with labels designed by each of their artist fathers. “We’re so excited,” Rebecca says. “We’re going to get our first bottles of wine the same year our babies are born.”

Jerry—who has joked, “when it’s meal time, you better make sure that meal is ready…because when Mama’s hungry, Mama’s hungry!”—makes cheeseburgers on demand. “I knew early on he would be a fantastic dad,” Rebecca says. “He’s a pragmatic, smart, savvy, enthusiastic person. He really lives his life with tremendous integrity, and he’s a healthy person in every single way.” As a pair, they plan to be extremely hands-on. And while Rebecca always thought she would be the disciplinarian, “I think he might be more of one,” she says now. “I’ve just surrendered to the fact that [parenting] will be the hardest thing I’ll ever do. I know my life will never be the same—but in the best way possible.”