A native of Phoenix, Arizona, Davidson attended Shadow Mountain High School. Her father is a principal at El Mirage Elementary School. She began doing commercial work and her acting coach Gene Fowler encouraged her to move to Los Angeles, California at a young age. Amy was not only cast on many shows with Kaley Cuoco but is also her step-cousin and they share the same agent, Terry Louisse Machlaclan.

Upon arriving in Los Angeles, Amy was cast in the Mary-Kate and Ashley Olsen series, So Little Time. She has also guest-starred on the drama series Judging Amy and the American sitcom Malcolm In The Middle, and has appeared in the movie The Truth About Jane. Most recently, Amy wrapped production on the Hallmark Channel film Annie's Point, opposite Betty White and Richard Thomas.

Davidson also starred in the film Goyband in which she stars as a young Orthodox Jewish girl who falls for an ex-boyband pop star (Adam Pascal) who performs at her family's hotel in the Catskills. Goyband's cast includes Natasha Lyonne, Tovah Feldshuh, Dean Edwards, Tibor Feldman, and Cris Judd.