Lithe Lithuanian Julija Steponaviciute is one busy high school student. Juggling calculus and catwalks, the vivacious Virgo walked for Gucci Resort, Calvin Klein, Hervé Léger, Dolce & Gabbana, Marc by Marc Jacobs, L’Wren Scott and Jason Wu at the spring collections. Look for the head-turning teen in Italian Vogue. Step on! (IMG)