Béatrice Dalle was 20 in Betty Blue when she played the character 'Betty'.
That was over 38 years ago in 1986.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 59, and has starred in 60 movies in total, 54 of those since Betty Blue was released.
In Betty Blue, I think Béatrice Dalle looks: