If you diet now, you'll probably look too thin after all the fat is gone. (Look at Nicole Richie!!!) Try working out with heavier weights and eat enough to gain maybe 2 pounds of lean mass per month. For a girl that can be tough, but it'll add up. Once you gain muscle you'll give the illusion of having lower bodyfat levels. Don't starve, you probably have less fat than most people your age anyways! Good luck.