Anime about a girl, who becomes an adult by using magic and starts modeling
It can be Fancy Lala


  One day, nine-year-old girl Miho Shinohara is given two stuffed dinosaurs by a stranger. The stuffed dinosaurs come to life and present her with a magic sketchbook and pen. Within limits, and subject to varying degrees of control, she can draw in the sketchbook and bring the drawings to life. Miho can also transform into a teenage girl, whom she names Fancy Lala. Fancy Lala is scouted by Yumi Haneishi, the president of the talent agency Lyrical Productions, and begins the long road to stardom.