Demi Lovato may be just 18, but she's got the sassiness of a 21-year-old. The Camp Rock 2 star owned the stage at West Palm Beach's Cruzan Amphitheater earlier this week. Dressed in a fierce head-to-toe black ensemble, the "Wouldn't Change A Thing" singer looked like the little pop princess she is. Check out all the pics of Demi—if you think you can handle her seriously saucy attitude.