In 2006, she had a small film role in Step Up as Camille, Channing Tatum's character's younger sister. She provided the voice of Isabella Garcia-Shapiro and Jenny (until Season 4) in the Disney Channel animated series Phineas and Ferb from 2007-2015, and personally came up with Isabella's catchphrase "Whatcha doin'?". In 2008, she starred in the Disney Channel Original movie Camp Rock as Caitlyn Gellar, an aspiring music producer. Her reception in Camp Rock was particularly strong, with various media outlets suggesting it was about time she played a main character role having backed up for other big names such as Will Smith and Eminem. Stoner starred as Alice McKinley in the movie Alice Upside Down, based loosely on the Alice series, particularly The Agony of Alice by Phyllis Reynolds Naylor. This was her second starring role and, according to an interview that appears on the direct-to-DVD release, she states that this was the first time she has had to appear in every scene in a movie.