Sarah Stephens was discovered at the age of 16 when she won the Girlfriend Model Search in Australia. Since then, the Sydney-based stunner, now 18, is well-known for her creamy complexion and pillowy pout and has gone on to grace the cover of Russian Vogue and model for presentations of Gucci and Lanvin.

"I was under the radar at school," Stephens tells Usmagazine.com. "I think everyone was shocked when I won the competition. People my year didn't realize who I was." (Watch above).

"Back in Australia I wasn't really the hot girl," the former bass clarinet player says. "I was just sort of pale, and I don't think guys really liked me."

On September 3, Usmagazine.com met Stephens at Next Model Management (which boasts top models Molly Sims and Petra Nemcova among its roster) before embarking on whirlwind day of casting calls and fittings for her first New York Fashion Week.

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"You go to about 15 castings a day and can wait for up to two hours to be called," Stephens tells Us.

First stop: Watch Stephens at the Gap presentation casting, where she meets with world-renowned casting director Russell Marsh.

"At castings you walk and take a few pictures and they decide what girls they're going to pick for the show," Stephens explains.

Watch Stephens try on outfits for designer James Coviello (Winona Ryder is a fan) and glam up backstage at the star-studded Jason Wu show attended by Gossip Girl Leighton Meester and Vogue editor-in-chief Anna Wintour. Plus: Hear Stephens explain the world of modeling and meet Cameron Diaz's makeup artist, Gucci Westman.

Check back to the Style channel at Usmagazine.com on Friday, to see Stephens walk in the Jason Wu show.

See photos of stars at Fashion Week.

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