Sophia Myles was 18 in Mansfield Park when she played the character 'Susan "Susie" Price'.
That was over 25 years ago in 1999.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 44, and has starred in 27 movies in total, 25 of those since Mansfield Park was released.
In Mansfield Park, I think Sophia Myles looks: