Kelly Stables was 24 in Pride and Prejudice when she played the character 'Lydia Meryton'.
That was over 20 years ago in 2003.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 46, and has starred in 20 movies in total, 19 of those since Pride and Prejudice was released.
In Pride and Prejudice, I think Kelly Stables looks: