Harriet Walter was 28 in The Imitation Game when she played an uncredited character.
That was over 44 years ago in 1980.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 73, and has starred in 56 movies in total, 56 of those since The Imitation Game was released.
In The Imitation Game, I think Harriet Walter looks: