That was over 18 years ago in 2003.
Today she is 27, and has starred in 46 movies in total, 36 since The Cat in the Hat was released.
In The Cat in the Hat, I think Dakota Fanning looks:
The Cat in the Hat scores 5 out of 10 on The Movie Database.
Dakota Fanning's first acting role was as 'Clairee' in Father Xmas, released in 2001 when she was 7.