Born as Phyllis Callow, Douglas (daughter of famous assistant director Ridgeway Callow) made her feature acting debut at the age of two in the epic classic Gone With the Wind (1939, photographed by Ernest Haller), although she was not credited for her work. She later appeared (again, without credit) in the film Raintree County, which also featured DeForest Kelley. In 1959's Girls Town she played the character Eleanor alongside Elinor Donahue. She also appeared in two episodes of Batman (both with Lawrence Montaigne).