Mitchell was born in Toledo, Ohio on November 4, 1919. She studied at the University of Toledo and at the University of Michigan. Mitchell was married to Julian Frieden from 1946 until they divorced in 1974. Then she was married to Jay Livingston from 1992 until his death in 2001. She had two children with Frieden. Mitchell died on November 11, 2013 in Westwood, California from natural causes, aged 94.