MOLLY SIMS IS that girl. The one your husband or boyfriend oohs and aahs over and you don’t mind—because you do the same. The one with Hollywood access who would rather spend a holiday weekend at home with a girlfriend of 17 years, a relationship built before the red carpets and runways. She’s quick to give makeup tips (it’s all about tinted moisturizer, ladies) yet leaves the house for her Tracy Anderson workouts sans makeup, paparazzi be damned. She seems to have done it all, but when you talk to her you get the feeling that her best is yet to come.

Sims is coming off of a hectic yet rewarding acting run, which included a five-year stint on the hit NBC show Las Vegas and roles in several notable films (Yes Man with Jim Carrey and Fired Up!, among others). We caught up with her on the brink of a new chapter, one that further defines a woman with a sharp business sense and a grounded commitment to give as much as she gets.

Most recently she launched a new jewelry line, Grayce by Molly Sims, a collection at once wearable yet effortlessly glamorous, much like its creator. The line includes chic metal knots and Deco-inspired necklaces, chunky cocktail rings and layered pearls. The inspiration? Her mom, who started collecting vintage jewelry more than 20 years ago from estate auctions and her many years traveling abroad. “I wanted my jewelry to represent me, in the way that I’m not one lifestyle,” Sims says. “I was white T-shirt and blue jeans today; yesterday I was at an event as glamour girl; the day before, bohemian. I love layering and mixing different elements. Whether it’s retro touches or understated glamour, it’s always representative of me.”

Lassoed by HSN, the collection is priced at under $100 and “the pieces have a feminine, approachable feel,” she explains. “Glamorous can be no makeup and jeans with a little cross or Star of David, or a little fireball at my neck with nothing else. It’s also how you wear it. I didn’t grow up with gazillions of dollars, so it’s mixing high-end and low-end. That’s what I still do. My $40 find sometimes means more to me than my $700 find.”

Sims is perhaps most jazzed about her newest role as ambassador to Population Services International’s Five & Alive program. The global health organization, whose board of directors includes actress and activist Ashley Judd, is dedicated to programs targeting malaria, child survival, HIV and reproductive health. “To date PSI and Five & Alive have purified 40 billion liters of water and distributed close to 50 million mosquito nets,” Sims explains. “If a child gets malaria they can die within five days. It’s raising awareness. If we get one more dollar it’s one more step.”

The Five & Alive program is specifically aimed at improving the health and lives of children five and under, and is making impressive headway in more than 30 countries. Sims is the face of its recent United Against Malaria campaign and traveled to Haiti for the first time in October to launch a new youth center built in part by HSN donations. “Haiti is the poorest nation in the Americas. It’s undoubtedly the women who suffer the most, traditionally the young girls who are taken from little villages and forced to work in cities as domestic servants,” Sims says. “For those lucky enough to escape, they have few options for survival, so they start working in brothels or on the streets, and usually get pregnant. That’s where children under five come in. At the base of it, it starts with education. I want to meet these young girls. I want to hear their stories.”

Sims has long been involved with children— she’s been working with the Casa Hogar Sion orphanage in Tijuana for years—which naturally leads to questions about starting her own family. “I will adopt and I definitely do want to have my own children,” she says. As we talk, Sims cues her friend’s toddler to recite “tur-tle” and “pick-le.” Laughing, she adds, “Absolutely, my biological clock is running. I find if we start with our little ones, it may not be where the most improvement is, but it’s where the most hope is.”

Though globe-trotting for humanitarian efforts creates a demanding schedule, her acting career doesn’t takes a back seat. She has been cast in Hickory Nation, an indie project by director Rebecca Cook set for release in 2011, in which she plays a grieving woman struggling with the death of a child. “It’s more of a dramatic turn for me,” says Sims. “She’s a schoolteacher and it’s about how she deals with that death and the relationship to her own father. It’s kind of like Crash because it has three or four intertwining stories. I love that format.”

Between film projects, trips to Haiti and starting a new jewelry line, how’s a girl to stay in shape? “Tracy Anderson,” she says. “It’s completely changed my body. It’s incredible, I promise you.” Also an avid outdoorswoman (who can forget that 2003 Sports Illustrated fly-fishing shoot in Meeker?), Sims loves to ski. She’s looking forward to her next ski vacation in Aspen and perhaps being pampered by The Little Nell. “I just love Colorado. The fireplaces, the lights, the mountains, the trees and that fresh, pure white snow,” Sims says. “I can’t wait to get out there again.”

A bicoastal career keeps her bouncing between New York and Los Angeles, but she still makes time to return to the South, having grown up in Kentucky. “I miss my mother’s cooking—biscuits, red velvet cake, chicken and dumplings,” she says in her charming Southern accent. “And I also miss that humid heat. There’s a certain smell, a certain thickness to the air. I’ll look at a firefly and it triggers such memories.”

Though mum about her dating scene, when asked what has her most fired up these days, she’s forthright. “I’m really excited about my life right now. I’m excited about the unknown. I’ve made some really great changes. I’ve been traveling, seeing a lot of friends and family. It’s great taking a deep breath and knowing that, Hmm, you never know what’s around the corner.”