Yes, Tyra Banks has taught the world how to work a runway and “smize” (a.k.a. smile with your eyes) for the camera, but her main goal has always been to “expand the narrow definitions of what’s considered beautiful,” she tells PEOPLE. Enter-with a fierce strut!-Sheridan Watson, the 17-year-old, size-14 winner of the Fiercely Real Teen Model Search, which Banks hosted for plus-size teens on The Tyra Banks Show. “She is refreshingly confident about her body and who she is,” Banks says. That wasn’t always the case. At 14, Watson weighed 230 lbs. and “was extremely unhealthy,” she admits, as well as the subject of brutal teasing, like when a classmate threw French fries at her and yelled, “Time to feed the cow!” Says Watson, a West Orange, N.J.-based high school senior: “That was the worst.” After a stint in weight-loss camp, the 5’10” Watson-who now has a three-year contract with Wilhelmina Models-got down to 190 lbs. and says, “I’m healthy and comfortable in my body.” Which is definitely something to smize about.