Rosemary Jeanne Harris was born in London in 1923. She went to school in Weymouth, then to St Martin's Central and Chelsea schools of Art and the Courtauld Institute of Art. She was in the Red Cross Nursing Auxiliary Westminster Division during the Second World War.
She started worked as a picture restorer and at the Metro-Goldwyn-Mayer film studios. She was the Children's Book Reviewer for the Times newspaper from 1970 to 1973.