Audrey Hepburn was 36 in How to Steal a Million when she played the character 'Nicole Bonnet'.
That was over 57 years ago in 1966.
In 1993 she died aged 63, starring in 58 films in her career, 35 of those after How to Steal a Million was first released. If she were alive today she would be 94.
In How to Steal a Million, I think Audrey Hepburn looks: