Olivia Wilde was 19 in The Girl Next Door when she played the character 'Kellie'.
That was over 20 years ago in 2004.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 40, and has starred in 49 movies in total, 48 of those since The Girl Next Door was released.
In The Girl Next Door, I think Olivia Wilde looks: