Hayden Panettiere was 7 in The Object of My Affection when she played the character 'Mermaid'.
That was over 26 years ago in 1998.
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 35 movies in total, 34 of those since The Object of My Affection was released.
In The Object of My Affection, I think Hayden Panettiere looks: