As if on cue at the sound of a knock, Molly Shattuck's children appear at the front door of the palatial Roland Park 1926 brick home she shares with her husband, Mayo Shattuck III, chairman, president, and CEO of Constellation Energy.

"Hi, I'm Spencer," says their 13-year-old son, greeting a visitor with his bright smile. "And I'm Lillian," says her 8-year-old daughter, wearing a pink-and-green Lilly Pulitzer sheath.

"This is Lizzie Mae," says Spencer, introducing the family Maltipoo. And within moments, the middle son, Wyatt, 10, emerges, and offers a handshake befitting the son of a Fortune 500 CEO. Then, with another touch of perfect stage timing, Shattuck herself, a diminutive dynamo with the most boffo body in Baltimore, stands bare foot in the dramatic brick-red foyer in a form-fitting periwinkle dress. "Hi, I'm Molly," she says simply.

With her luggage ready to roll out the front door as the family prepares to leave within hours for the San Francisco wedding of Mayo's oldest son (from his first marriage), Shattuck herself is on a roll these days. She's juggling a new exercise DVD (in which she and her kids demonstrate waist twists and proper jump-rope technique) called The Vibrant Living Workout, as well as an eponymous website (mollyshattuck.com) offering fitness and nutrition tips, recipes, and thoughts on volunteer work.

"The reason I created 'Vibrant Living' is because, for years, people would say, 'What is it you do?'" says the 5-foot, 4-inch, 110-pound Molly, who's now curled up on a pink and white chair in her cheery sunroom, a blue Molly Shattuck-brand, BPA-free water bottle at her side.

"What's the secret? I tell people you have to be well hydrated—I don't drink coffee, tea, or soda," she says. "You have to move your body every day and eat right, but deprivation is not realistic. You have to have a balance of vegetables, proteins, and carbohydrates."

Though she loves being active, Shattuck is a homebody at heart. "I love to be home," she says. "I love to cook, I love to bake, I love to do crafts, and I'd much rather have a dinner party at home than go to a restaurant."

With her storybook home—okay, make that a storybook, five-bedroom, 5.5-bathroom manse with a pool and new exercise room—three kids straight out of central casting (all of whom profess to eat their vegetables!), a milestone career as the oldest cheerleader in NFL history (at the ripe old age of 38), a one-episode stint on Fox's Secret Millionaire, and a husband who happens to be one of the wealthiest men in Baltimore (reported compensation of $15.7 million in 2010, according to The Sun), is it any wonder that everyone wants in on the secrets of the former homecoming queen?

Though she is blonde and beautiful, the real secret behind Molly Shattuck (a ringer for actress Kristin Chenoweth) is that she's not just another pretty face. Growing up in a modest house down the road from her grandparents' farm in Kittanning, PA, she was far from being born with a silver spoon in her mouth. In fact, her parents, married at 18 and 19, probably didn't even own one. "It was nothing fancy," she says, laughing.

"My parents instilled the idea of hard work in us," says the now-44-year-old Shattuck, who was the middle child of three girls. "My mother had a beauty shop for 40 years—it was like Steel Magnolias. I literally grew up in the beauty shop and played with 'curlies'—that's what I called curlers. When I was a newborn baby, my mom went back to work a week later. I grew up running the register at my Dad's gas station and worked in my aunt and uncle's restaurant as a waitress."

Shattuck's childhood was a happy and uncomplicated one. "We rode our bikes every day," says Shattuck. "We played in the creek." And she has always loved to exercise. "We couldn't afford dance lessons," she recalls, "but I taught myself to tap and, in grade school, because tennis and cheerleading were the only options for girls, I was a cheerleader."

By high school, Shattuck had become captain of the cheerleading squad, but even more life-altering, while on a trip to the Grand Canyon in her senior year, she made a vow to herself that she still honors every year—she wrote a bucket list. "I came up with the idea of making a list of 10 things I wanted to do with my life," says Shattuck, "and I still have that list and keep a list to this day. It's like my road map." Among her goals: "I wanted to get married and have a family" (she married Mayo in 1997 and gave birth to Spencer the following year); "I wanted to go to college" (she attended Indiana University of Pennsylvania, where she majored in marketing and business administration); "I wanted to climb Mt. Kilimanjaro" (she completed her ascent in October 2007); "I wanted to be a Dallas Cowboy's cheerleader" (she made the Ravens' team in 2005—close enough).

"I had been pregnant or nursing, pregnant or nursing," says Shattuck. "Right after I stopped nursing Lillian, I said, 'I want to be a Ravens cheerleader.'" When Shattuck first heard about the auditions, she was in Florida. "Mayo called me and said, 'The auditions are on Saturday.' I flew back, but I needed photos, and I didn't even own a bikini. Mayo took pictures of me in a bra and underwear. I was literally standing in our bathroom for them."

After five cuts, Shattuck (she used the name "Molly S." to audition) got her pom poms the old-fashioned way: by earning them. "I didn't want to make it because of his influence," says Shattuck. "I wanted to make it legitimately."

Though she still coaches part-time, ultimately, she hung up her uniform for more time with her moppets. "There's nothing better than looking out at 70,000 fans," says Shattuck, "but it was an easy decision. My kids were 4, 6, and 8 at the time, and I needed to be there for them."

Relics of Shattuck's cheerleading glory days are still on view in her home: Until recently, the walls of Mayo's first-floor bar area were adorned with publicity shots framed from the pages of Sports Illustrated, USA Today, and People. Years ago, when the bar was being built, Shattuck surprised her husband by having glass-topped drawers made to exhibit his collection of golf balls. "Mayo likes to golf," says Shattuck. "He collects golf balls from every course he has ever played—from Augusta to Pebble Beach—and I had these drawers made to display them. He was thrilled when he saw them."

The Shattuck home is a study in contrasts. A Lalique vase given as a weding present is displayed in the living room near her children's teething rattles; precious oil paintings and heavy gold damask curtains are hung next to Wyatt's Jackson Pollack-style abstract oil paintings in the music room; in the living room, a glass case displays a pair of hand-painted sand dollars from the couple's wedding on Maine's Chebeague Island.

Throughout the space, family heirlooms from both sides are also added to the mix. Shattuck's beloved grandparents handed-down porcelain dishes are on display in the dining room, and an inherited settee is perched on the upstairs landing in the hallway. Heirlooms from Mayo's childhood (spent in tony Hinghan and Cohasset, Massachusetts) are also there, including a coffee table and side tables.

Despite the prevalence of priceless antiques and formal furniture, no room is off limits to the Shattuck brood ("We sit everywhere," offers Spencer), and, nearly every room is peppered with charitable projects and handmade goods, from cookies for a homeless shelter on the kitchen counter to handmade welcome bags for Mayo's son's wedding on the foyer floor.

The heart of the home is the charming, surprisingly old-fashioned kitchen that has undergone a few facelifts. "We renovated when we first moved in 1997," recounts Molly, "and then nine years ago, we did an expansion so that we could all fit around the kitchen table. At the same time, we converted the garage into a family room. We really spend all of our time in these rooms."

During the course of the kitchen updates, many elements of the old kitchen were retained, including the original, white flat-front cabinets. "The quality of the cabinets is better than anything you could get today," says Shattuck. "And I love the character of the old. When we bought this, it wasn't 'cool' to buy these old houses, but I love their charm. We wanted to preserve what we could. We love the history of the house."

Shattuck and her husband tend to agree in their approach to decorating. "Our taste is so similar," she says. "He'll be in a store and say, 'I saw this great piece,' and I will have already taken a picture of it. I'll say, 'You mean this?'"

Shattuck, who met her husband as a marketing associate when she literally bumped into him at Alex. Brown & Sons while walking backwards out of a colleague's office, fills her hours with charity work and volunteers with her children, whether building hoop houses at Real Food Farm or making sandwiches for local soup kitchens. One of her more recent projects: orchestrating a partnership between United Way of Central Maryland and Baltimore City and environs to focus on making affordable, fresh food available to underserved communities in Baltimore.

"It's about raising awareness," says Shattuck, who is donating part of the proceeds from her fitness video to the project. "There's nothing more basic than healthy food, and it's what people aren't putting into their bodies that is making them sick."

Though Shattuck could certainly be living a life of idle luxury, she instead contributes to the community nearly every waking hour, not just with money, but with her time, too. She and Mayo are co-chairs of the United Way of Central Maryland. She's a member of the Board of Overseers at the Baltimore School for the Arts and is on the national advisory board for the The Johns Hopkins Children's Center, to name just a couple of causes. In fact, her extensive involvement has earned her several awards for her charitable work.

Shattuck sees volunteer work as something that should be an integral part of raising a family. "You have to teach your kids to volunteer at a young age and make it part of their lives," she believes. "It teaches them to be nice to everyone. It teaches them values in a real sense and not just the words."

It's a lesson the down-to-earth Shattuck learned firsthand from her own childhood. "I never would have dreamed any of this," says Shattuck standing next to an exquisite inlaid buffet in the dining room. "Things make people temporarily happy, but it's really all about who you are and how you live your life and doing things with a purpose."