Kristen Stewart was 8 in The Thirteenth Year when she played the character 'Girl in Fountain Line (uncredited)'.
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 34, and has starred in 58 movies in total, 54 of those since The Thirteenth Year was released.
In The Thirteenth Year, I think Kristen Stewart looks: