Carey Mulligan was 19 in Pride & Prejudice when she played the character 'Kitty Bennet'.
That was over 18 years ago in 2005.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 38, and has starred in 34 movies in total, 29 of those since Pride & Prejudice was released.
In Pride & Prejudice, I think Carey Mulligan looks: