Christina Applegate was 39 in Alvin and the Chipmunks: Chipwrecked when she played the character 'Brittany (voice)'.
That was over 12 years ago in 2011.
Today she is 52, and has starred in 50 movies in total, 10 of those since Alvin and the Chipmunks: Chipwrecked was released.
In Alvin and the Chipmunks: Chipwrecked, I think Christina Applegate looks: