Stone wanted to act since age four; she wanted a career in sketch comedy initially, but shifted her focus toward musical theater, and took vocal lessons for several years. Her acting debut, at age 11, came in a stage production of "The Wind in the Willows", playing the part of Otter. Stone was homeschooled for two years, during which time she appeared in sixteen productions at Phoenix's Valley Youth Theatreincluding "The Princess and the Pea", "Alice's Adventures in Wonderland", and "Joseph and the Amazing Technicolor Dreamcoat"and performed with the theater's improvisational comedy troupe. Around this time, she traveled to Los Angeles and auditioned unsuccessfully for a role in Nickelodeon's "All That". Her parents later sent her for private acting lessons with a local acting coach, who had worked at the William Morris Agency in the 1970s.