That was over 12 years ago in 2009.
Today she is 35, and has starred in 39 movies in total, 27 since Jennifer's Body was released.
In Jennifer's Body, I think Amanda Seyfried looks:
Jennifer's Body scores 5.3 out of 10 on The Movie Database.
Amanda Seyfried's first acting role was as 'Karen Smith' in Mean Girls, released in 2004 when she was 18.