Vidal was born in Whitestone, Queens, the daughter of Josie, a secretary, and Manny Vidal, a tax consultant and businessman. Her parents moved from Puerto Rico and settled in Manhattan, New York, where Vidal and her two sisters Christina and Tanya were born. She also has a brother named Christian. After Vidal finished her elementary education, she auditioned and was accepted in the High School of Performing Arts. When she graduated, Vidal went to work with La Familia Theater Company, alongside Raul Julia and Julia Roberts. Vidal was 14 years old when she acted in the theater series Oye Willie and later on made her feature debut with a small role in Delivery Boys. Soon, she was working in T. V. with parts in shows such as The Cosby Show.