She has two children. In 1960, she gave birth to an illegitimate son, named Mark. The father of her son has never been identified, but he is apparently a well-known actor, with whom Jameson had a very brief 'relationship'. Jameson had her son adopted. His name was changed to Nigel, and many years later, he tried to establish contact with his biological mother. She met him once, but resisted further contact, writing, 'I have no sense of being your mother.' In addition, Jameson has a daughter, Lucy, born in 1977.