Jean Simmons was 14 in Give Us the Moon when she played the character 'Heidi'.
That was over 80 years ago in 1944.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
In 2010 she died aged 81, starring in 75 films in her career, 75 of those after Give Us the Moon was first released. If she were alive today she would be 95.
In Give Us the Moon, I think Jean Simmons looks: