Diane Keaton was 23 in Lovers and Other Strangers when she played the character 'Joan Vecchio'.
That was over 54 years ago in 1970.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 78, and has starred in 73 movies in total, 70 of those since Lovers and Other Strangers was released.
In Lovers and Other Strangers, I think Diane Keaton looks: