Linda Cardellini was 21 in Good Burger when she played the character 'Heather'.
That was over 27 years ago in 1997.
This was her first recorded movie acting credit (although may not technically be her first actual acting role).
Today she is 48, and has starred in 38 movies in total, 35 of those since Good Burger was released.
In Good Burger, I think Linda Cardellini looks: