Like most teenage girls, 17-year-old Madelyn Rosario is enamored with this spring's prom dresses.

She loves the trendy princess gowns and body-skimming mermaid frocks made popular on this year's red carpets by the super-slim Miley Cyruses and Taylor Swifts.

But at 5-foot-3 and 170 pounds, Rosario is a confident, well-dressed teen - who is a solid size 14. In the discriminating world of fashion, that qualifies her as plus-size.

"Up until now, this is the biggest night of my life," said the Pennsauken High School junior. Her fashion sense is a cross between punk and A-line-dress girly.

She will be attending her junior prom Friday with a group of her girlfriends and she's psyched about shopping for a dress. However, when the conversation turns to size, she gets shy.

"Sometimes it's hard for me to find clothes that fit right," Rosario said.

It's difficult for grown women to feel the fashion playing field is level if being a certain size limits their options. Even women who don't consider themselves plus-size can't buy right off the runway because most designers don't make those pieces larger than a 12.

But it's especially hard when your teen-infused tastes skew toward Bebe and your proportions require Lane Bryant. Just last week, the old sentiments of Mike Jeffries, CEO of Abercrombie & Fitch - the store that doesn't carry any women's wear bigger than large - got renewed attention when Robin Lewis, coauthor of The New Rules of Retail, contended in an interview with Business Insider that Jeffries "doesn't want larger people shopping in his store, he wants thin and beautiful people."

With that size elitism common in the industry, how does a young woman who isn't industry-thin find the ombre dress of her dreams when she's not a barely-there size 2, or even a curvy 10?

Statistically speaking, Rosario's shape is more prevalent than that of sliver-of-a-British-model Cara Delevingne - famous partly because her thighs don't touch - that the fashion industry caters to.

According to a 2012 report from the Washington, D.C.-based Institute of Medicine, one-third of children ages 6 to 19 are overweight, and the rate of obesity among adolescents has more than tripled from 5 percent in the early '80s, to more than 15 percent today.

As obsesity rates rise, ironically the criticism gets louder. Armchair fashion followers often take to social media to insult sartorial choices they deem inappropriate for larger people.

Remember all the tweets that scolded British pop singer Adele for the long-sleeved Valentino print dress she wore to the Grammy's - as if people bigger than a certain size had no right to wear florals?

"These days we have body-image messages coming to us in surround sound," said Robyn Silverman, a northern New Jersey-based body-image expert and author of Good Girls Don't Get Fat: How Weight Obsession is Messing Up Our Girls and How You Can Help Them Thrive Despite It.

Teenage girls idolizing svelte models is nothing new, Silverman said, but social media adds a new twist to the "not good enough" feeling. Teens, she said, often Photoshop their own pictures to give themselves whiter teeth, a thinner jawline, and yes, Delevingne's thigh gap.

"For a girl that's plus-size, the messages are pervasive and consistent that fat is bad and thin is good," Silverman said. "So it's hard for a teen to feel good in the moment, if her back is bulging out of a dress."

Rosario, carrying a Teen Vogue and a cup of Starbucks, is ready to hunt for the perfect junior prom dress on a recent Saturday afternoon at Cherry Hill Mall. She looks of-the-moment cute wearing a button-down denim shirt and miniskirt, a navy blue shrunken blazer tossed over her arm.

Rosario is very familiar with the layout of the mall; she walks through it three times a week to get to L.A. Fitness. In the last five months, Rosario has dropped 20 pounds working out on the elliptical machine and embracing healthier food choices courtesy of her stepmother.

"I've always been a little chubby," she said, referring to her undisciplined diet of fried foods as a child. After she moved in with her father, things changed.

"When the doctor said I was obese, I was devastated," she said. "I didn't want to talk about it, I wanted to do something about it."

In keeping with Pennsauken High's "Night in Paris" theme, Rosario is looking for a romantic dress in a neutral tone. Shimmer would be nice, of course. But she's worried about finding a dress that flatters her stomach and arm problem spots. She's hopeful and confident.

First stop, Nordstrom. After a cruise through the special-occasion gowns, Rosario's eyes widen as they land on a coral tea dress with a lacy overlay. She takes it to the dressing room and the size 12 fits, but it gaps in the back and it's too matronly.

"I feel like I'm going to church," Rosario yells from the dressing room.

Rosario's sense of fashion is spot-on. She knows what she likes instantly. Her fashion icons include Sarah Jessica Parker's Sex and the City character Carrie Bradshaw (in fact, her room is the same robin's egg blue as Carrie's apartment in the movie), and Gossip Girl's Blair Waldorf, played by Leighton Meester.

"There aren't many girls my size that I can look up to," Rosario said. "But when I read the blogs, I think that people are starting to realize that not all girls are a size 0."

Turns out Nordstrom was too old-school for her taste. Also, with a $250 budget, the pieces were a bit out of her price range, so after a quick, obligatory walk through H&M, she stopped in Arden B. Pay dirt! The specialty store was having a 40-percent-off dress sale. She scooped up a cobalt blue peplumed dress with an exposed zipper along the back, a sparkling coral tube dress, and a silver-and-white color-blocked sheath.

Some zippers didn't go up all the way, others revealed bulges. But the cobalt blue dress was a good look.

"It fits me in all the right places," Rosario said.

But she put the dress on hold. It was still a little too diva-ish for her taste.

Why not try Macy's? That turned out to be a good move. The prom section was a glittering treasure trove of saturated tangerines and blinged-out flesh tones. There were girls shopping with their mothers and rock music was playing. Rosario grabbed three dresses.

And the day's winner: a strapless peach dress with a sweetheart neckline, ruching, and sparkling appliqués by B. Darlin for $160.

It was cinched at the waist and full of crinoline flounce. Rosario held the hem of the dress between her index and forefingers and modeled. Prom perfection.

"I feel like a princess," she said.

As well she should.

Contact fashion writer Elizabeth Wellington at 215-854-2704 or ewellington@phillynews.com. Follow her on Twitter @ewellingtonphl.