Colleen O'Shaughnessey was 35 in Horton Hears a Who! when she played the character 'Angela / Additional Voices (voice)'.
That was over 16 years ago in 2008.
Today she is 52, and has starred in 18 movies in total, 13 of those since Horton Hears a Who! was released.
In Horton Hears a Who!, I think Colleen O'Shaughnessey looks: