Shirley MacLaine was 20 in The Trouble with Harry when she played the character 'Jennifer Rogers'.
That was over 69 years ago in 1955.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 90, and has starred in 107 movies in total, 107 of those since The Trouble with Harry was released.
In The Trouble with Harry, I think Shirley MacLaine looks: