Holdridge was born Cheryl Lynn Phelps in New Orleans, Louisiana. Her mother, Julie A. Phelps (1908–2003), was a Dancer who performed on Broadway with her partner, Dick Mason; Cheryl's biological father is unidentified. Shortly after Cheryl was born, Julie moved with her new daughter to Burbank, California. In 1950, Julie married Herbert Charles Holdridge, a retired Brigadier General active in fringe political movements. He adopted Cheryl in 1953 and gave her his surname.