Complex sentence: His mother, known as Dodie, was unconventional for her time; an actress herself, she smoked, wore trousers and drove cars--all unusual for women at the time--and was even a theatre administrator, helping Henry Fonda begin his acting career.
Split into simpler sentences: His mother, known as Dodie, was unconventional for her time, she smoked, wore trousers and drove cars. An actress herself and even a theatre administrator, she helped Henry Fonda begin his acting career.