She was the princess and they were on Stephanie Patrol: Instamatic-toting housewives, high school jocks on crutches and baby yuppettes like Karen Reece, a teen-tabloid junkie playing hooky from class to beg an autograph from a Grimaldi.

"I like her much better than Lady Di," swooned Reece, giggling after the white Cadillac that deposited the live princess at the suburban shopping mall to promote her eye-popping line of $100 (gold and silver lame') bathing suits for perfect bodies.

"She's not so goody-goody," said Reece. "She's posed in her own bathing suits. They're sort of provocative, don't you think?"

"And," piped up a friend, "she doesn't always do what her father tells her!"

There you have it, an extraordinary phenomenon: adoration for a self-styled royal rebel who, rather than take the easy way out and sun her life away on the Riviera, has taken her Paris designs to America's red clay outback in the name of profits, hype and honor. A working-girl princess?

"I just decided to work and do my own thing, instead of sitting back and enjoying life," says Stephanie Marie Elizabeth Grimaldi, 21, third child of the late actress turned princess Grace Kelly and Prince Rainier of Monaco. "That's not the way I want to live. I can't stand doing nothing. That's how I was brought up."

It is the American debut for her swimsuit line Pool Positions, a takeoff on "pole position," her once favorite spot to watch Grand Prix racing on the winding, coastal roads of the French Riviera in a previous incarnation.

But doesn't the conservative South, with its share of magnolia ladies who turned up their noses at the suits ("I don't have the body to wear one, and I don't want my husband looking at anyone who does!") seem a rather odd place to premiere cutting-edge exotica?

Not for a local department store chain named Rich's, which scored a brilliant merchandising coup with a half-million-dollar deal for the suits -- and Stephanie.

So, voila , here she is, sipping a beer and puffing on a cigarette, sunglasses pushed up on her head, dark brown hair swept back in a boyish, Fabian-style cut ("It makes me look more sophisticated"), a blue Chanel suit hanging in stunning fashion on a trim, broad-shouldered frame.

"We wanted to show people in fashion that two young girls with an idea in their heads can be very professional, even if they're young," she says. "In France, nobody believes that young people can do anything. It's incredible."

"Ha-ha-ha-ha!" gloats Alix de la Comble, 30, an attractive brunette, "best friend" and design partner. She's just savoring the sweet revenge of success, the limos, the press, the three-bedroom penthouse suite at the Marriott Marquis. Friends and family warned them against breaking away from Christian Dior, where they worked as design assistants to Marc Bohan, to go it alone in a "sleazy" studio in a rough neighborhood.

"But we had to get out of there," says Stephanie. She was daydreaming of fun and sun in Mauritius. It was cold and snowy in Paris, November 1984, and she couldn't find a bathing suit she liked -- so she drew one and showed it to Alix.

"Great!" said Alix. "Let's do it."

They borrowed money from their brothers, scraped up what they had (Stephanie chipped in her allowance, too), counted a meager 180,000 francs to keep them in croissants and thread and went to work in one room with Atmo, Stephanie's giant German shepherd ("He eats meat -- otherwise, he eats people"), named for her favorite nightclub.

"We began to dream of going places," says Alix.

"To the beaches," says Stephanie. "So we began designing bathing suits we could wear."

As the buyers tell it, Rich's execs went gaga over the fledgling line of expensive suits and cover-ups, elegant and glittery enough to double as evening wear for trendy, aerobic-happy condomaniacs down South, and signed them on the spot. This was, of course, after Stephanie herself modeled one.

"She's got a fabulous body," says Richard Carty, director of fashion marketing. The line later won applause at last fall's debut in Paris, and the young women packed up their sketch books and sashayed over to classier Place Vendome.

But the market is still out on how their daring one-piece maillots, carried here and at Macy's and Bloomingdale's in New York, will fare off the racks. There are deep plunges in front and high rises in back. Some are white and you know what happens when they get wet. Of course, Bo Derek and hard young bodies who flit from spa to spa should delight in their drama.

Otherwise, the suits show no mercy for cellulite or women without top plastic surgeons. After all, how many American women look as fit as a James Bond movie model? Which is how fit you have to look to really fit, right, Steph?

She shrugs, "You can be a little chubby."

Don't believe it for a minute.

At the Lovett School fashion show last Thursday, 1,400 women packed into a gymnasium filled with yellow balloons to ogle the suits, some held up by multicolored, suspender-style straps. Add a tight miniskirt and jacket cover-up and you have an outfit that might run $300.

"Fabulous," gasped housewife Caroline Harkelroad, a literary agent turned mother of three. "I'd spend the money if I had the body, but I wouldn't dare wear one in the water. They look like they'd come off the minute you hit the pool -- and you'd get weird-looking suntans."

"I'd like more on the bottom and less on the top," sniffed a blond housewife who happened to be pregnant.

But the suits weren't sexy enough for Hayes Hitchens, assistant principal and one of the few men agape. "But I'm a single guy," he winked.

Then it was into a back room for a TV interview. Stephanie was giggling. "I either giggle or I cry." She appears painfully shy, but warms up with friends like Alix.

"We're very different," says Alix. "She's much more, how do you say, spontaneous. If I'm sad, I don't cry."

"Yeah," says Stephanie, who sees herself as happy and upbeat with an expressive "Mediterranean" temperament. She's quick with witty one-liners, but sometimes she frowns.

"Souri," said Francois Marchand, her curly haired business manager, "it's much better when you smile."

The spotlight makes her sweat, always tittering about the juvenile prankster who attended three schools before graduating from a Paris lyce'e, speculating over accounts of a jilted young Paul Belmondo, rumor-mongering about a bad-girl image of wearing leather jackets and gum chewing at fashion shows, wondering how the British Rover plunged off the road four years back, killing her mother and injuring Stephanie. So she laid out ground rules for her visit: no personal questions.

There's still lots to talk about, like what the vamp, sex-kitten suits say about fashion trends.

"You see more tight skirts today," she says. "Women want to look more feminine. Baggy clothes are out. They don't want to hide their bodies. Look at all the aerobics and gymnastics going on."

She stays in shape by running her dog and water-skiing back home. "Women have much better bodies and they want to show them off," she says. "They want to be sexy. And that's very good for us."

Back in the limo, she takes a ham sandwich and a Michelob on the run. Stephanie, who hates "princess" before her name, flips channels on the car TV, searching out favorite soaps. Hooked during a five-month stay in New York, she tried to detail plot for her baffled partner, then gave up: too much intrigue. Then it was off to one mall in the shadow of a Confederate battlefield to autograph swimsuit photos.

"Rich's is proud to present Stephanie of Monaco and her partner . . .," cooed the emcee as shutters clicked, applause broke out and fans like Chris Brackett, 17, a star soccer player who broke his leg last week, limped forward on crutches.

"I've seen every one of her mother's movies and if she comes from Princess Grace, that's good enough for me," he said. He aimed to frame her picture.

Indeed, if hype is hip and hip is hype, there's no hypester hipper than a princess with a pitch. Just look at the crowd.

"I'm a royal watcher, I'll confess," said Jennie Koets, 17. "I like the way she does what she wants."

"Let's go chase her!" squeeled Courtney Daniel, 16, skipping school with friends to race after her limo. "I read her father didn't want her to model, but she's doing it anyway. She's a rebel. Wish we could do that, but we're not as brave."

They pressed forward, as curvaceous models in her swimsuits passed out pix and petite bottles of Evian. Stephanie squirmed to the rock beat of "Sexomatic" on the the music video as she scribbled away. "She doesn't act stuck up or royal," swooned Karen Reece.

Young women write the palace asking Stephanie for advice on parents, boyfriends, fashion. But what they most admire is how she appears to be breaking away, going solo and Making It. "Yeah," she says, "I get a lot of letters like that."

She was on the cover of Elle last year, but just before she was to launch her modeling career she cancelled a flurry of assignments. But she disputes accounts that her father banned her from modeling. "I never would have done it if he'd said, 'I don't want you to model,' " she says. "But he didn't."

Not that the prince was thrilled with the avalanche of offers last year. "Do whatever you want," he said, "but you'll see." She backed out at the last minute for medical reasons, said the palace.

Nor was he gung-ho about her fashion career. At first, she says, "he didn't believe in it, but we showed him we could do it."

Not that Rainier was the only skeptic. "Everyone said we were stupid," she says. "Everyone said, 'Quit now before you lose any money.' But we said, 'Forget it, we'll do it.' "

She pokes fun at herself. Take the three different schools she attended. "I went to a lot of schools," she laughs. "But I went to the same one for six years. That's pretty good. Then things started happening."

When she announced she wanted to forgo college to work, her parents said, 'Fine, work if you want to work,' " she says. "Caroline wanted to go to college, so she did."

Only Prince Albert, her brother, she says, is duty bound as heir-apparent.

After the mall, it was onward for coffee in a naugahyde booth at a local barbecue joint. Locals had no idea who she was. Later, she ate collard greens and fried chicken, sipping Korbel champagne (no more Dom Perignon by then) at an elegant southern supper for 100 friends of Jack and Mary Portman.

He runs the real estate development firm founded by his father; Mary heads a group that promotes foreign imports. On this night, she matched Stephanie with Jack's baby brother Jarel, 23, all 6 feet 2 inches of blond hunkorama, "an 'American prince,' " Mary quipped.

A hotel management trainee in San Francisco, he flew in for the night. Alix's escort was Jim Topping, 23, a Florida nightclub owner and Portman's college roommate.

Like any blind date, everyone was nervous at first, but Stephanie broke the ice by mixing vodka and tonics, and singing some French lyrics from a song she just recorded, "Irresistable." Then it was off to the party.

Rich's PR squad feared what they had heard might be "unpredictable" royal behavior, one company PR woman said, but Stephanie played the perfect princess. She spent three days here plugging suits, appeared in Birmingham Saturday at another Rich's store, and today jetted off for London to weigh in at Harrod's Monday.

Only a 30-minute stop was forecast chez Portman, but she perched on a stool in the kitchen and hung out for more than two hours.

Guests streamed in and out. One fortyish man who peaked in announced himself as a "dirty old man," then changed his mind. "No," he said, "I'm a dirty, middle-aged man."

"No," laughed Stephanie, "you were right the first time. Old."

One child presented her with a poem; another eyed her tight black pants, an oversized white tunic top, her Chanel earrings and gold bracelets and announced, "I liked your hair better in a magazine I saw." She said she aimed to let it grow out. A country band played "Rockytop," as a chef whipped up homemade biscuits.

Later, ever-present bodyguards in tow, she danced at the Limelight, a trendy disco, beneath a stage of women vying to be crowned "Miss Legs." (Gossip-mongers, take note that she ran from the limo holding hands with Jarel.)

"We had a blast," he said. "She's a very nice girl."