The first time Jillian Mercado thought seriously about becoming a professional model, she decided to seek out a mentor. So she pulled out her laptop and scoured the Internet for someone in the modeling world who looked like she did: someone with a physical disability. Someone who used a wheelchair.

That was six years ago, when Mercado was a senior studying fashion marketing at the Fashion Institute of Technology in New York, and disabled models were scarce. Her search came up empty.

"I didn't think it was a possibility," she says of the career she'd imagined. "Not because I didn't think I was worthy of it, but because I didn't see anyone else like me out there. It was just not a thing."

Mercado, who was diagnosed with spastic muscular dystrophy as a teen, has helped change that reality. Two years ago, she responded to an open casting call for a Diesel Jeans ad campaign on a whim — and wound up getting hired. (Why should we choose you? the casting questionnaire asked. Because I want to change the world, she answered.) Last year, Mercado signed with IMG Models, the powerhouse agency that represents top supermodels like Gisele Bündchen, Kate Moss and Heidi Klum alongside an increasingly diverse lineup of rising stars.

Mercado is one of them. On Thursday, she'll be among a dozen Latina models featured in a Target marketing campaign that will debut during Telemundo's Billboard Latin Music Awards — a career milestone that comes just a few weeks after she starred in the merchandise ads for Beyonce's highly-anticipated "Formation" tour.

For the modest 28-year-old Dominican American who was once tormented by middle-school bullies, appearing on prime-time TV and posing with Queen Bey's fashion posse still feels just a bit surreal.

"It's exactly what I hoped for as a young girl," she says. "I dreamed of having this opportunity."

Mercado's rapid ascent has been cheered by major media outlets as a victory for the 53 million disabled American adults who rarely see themselves represented in high-profile advertisements. But the fact that her appearance still attracts so much attention — that it's something to be pointed out and celebrated as an exception to the rule — means there's still a lot of work to do, she says.

"Ultimately, we're trying to normalize diversity," she says of IMG, which represents a wide range of models, including plus-size model Ashley Graham and Hari Nef, a transgender model, actress and writer.

"Campaigns should have real people," Mercado says. "People should see themselves in an editorial, in a magazine or a commercial."

She's not the first disabled model to find success in an industry driven by conventional beauty norms. Nordstrom used disabled models in its catalogs in 1997; Alexander McQueen featured double-amputee Paralympian Aimee Mullins in a 1998 runway show. But those early trailblazers were few and far between when Mercado first searched for a would-be mentor. A surge of breakthroughs have come in recent years: Danielle Sheypuk became the first model in a wheelchair to appear at New York Fashion Week in 2014; last year, actress Jamie Brewer and Australian model Madeline Stuart became the first models with Down syndrome to be featured at the event, the same year that British model Jack Eyers became the first male amputee to walk the New York Fashion Week runway.

Breaking in is hard enough — but the challenges don't stop there. For Mercado, who also works as a design consultant and fashion blogger, modeling involves inevitable hurdles that her able-bodied colleagues don't have to think about. Her disease, which causes progressive weakness and muscle loss, means that every outing involves careful planning and extra time; instead of hailing a cab, she requires a vehicle with a wheelchair access ramp. Not every location is as accessible as it should be: "Sometimes there are steps in the way, and the studio doesn't have an elevators," she says. During a shoot, there are certain movements and poses that are simply not an option for her.

But her team has always found a way to work around these issues, and she's never been cut from a campaign because of concerns about her disability, she says.

"There's never been a problem with the team not getting what they need to get from me as a model," she says. "There's never been an excuse where it's like — 'she has a disability, this is not going to work because the photos won't look nice.'"

Ironically, the opposite scenario can be a concern. Like other disabled models (including Eyers, who has said that he worries about being featured in campaigns as a "one-off sob story"), Mercado frets that the inevitable qualifier — a model with a disability — means some companies might be drawn to the promise of good PR instead of her talent.

"Some people immediately think, 'okay, this is going to get me press,'" she says. "And that always comes into mind when I do projects. You have to communicate to whoever you're working with and say, 'okay, what's the reasoning behind this shoot, what are we trying to do?'"

The answer, she says, should be the same one they'd give any model.

"If I'm a model and this is a clothing company and they want to showcase their stuff on me, that's great," she says. "That's all it should be."

Her cheerful confidence is hard-won; it took years for her to decide she loved her body, she says. She still remembers the misery of her adolescence, when classmates cruelly taunted her. "There were people who told me I might as well just give up, because there's no point," she says.

Her small body has more than a dozen surgical scars, she says, and she felt both nervous and excited when she decided last year to bare them for a shoot for the lingerie company Thistle & Spire.

"Even though I'm very outspoken with what I believe in, I'm very much of a shy person still at heart," she says. "But I wanted to take on a challenge, because people who have some sort of disability are often looked at as a fetish instead of someone who is sexy and empowering."

So she posed in a sheer black chemise, her bleached blonde hair cut in a punky pixie, her mouth set in a sultry pout as she leaned against the railing of a Manhattan rooftop deck.

Big Bird in a Small Cage 🐦 lingerie: @thistleandspire p: @thewinterbook mua: @audreyleacurry

A post shared by Jillian Mercado (@jilly_peppa) on

She liked reminding people that everyone can and should feel sexy in their own skin: "You shouldn't be ashamed of your own body," she says. "I hope in the years that I'm alive that there will be a Victoria's Secret model who has a disability, because that's considered mainstream sexy."

In the meantime, she's focused on her work and using her blog to encourage those who want to follow her example. When the next generation of disabled models searches the web for inspiration, they'll find her.

"I turned my weakness into my strength, and I feel like very few people have been given that opportunity," she says. "It feels like me looking at my younger self and telling her, 'everything's going to be okay.' I'm an example that you can do what you want, because …" she pauses. "Just because! That's it. You just can."