All I can remember was the little girl had red hair and a yellow dress. I believe it was environment-related and I think she changed from a real girl into a cartoon through out the movie and then back into a real girl. I want to say there were two movies and one had to do with her saving a whale.. Does ANYONE remember this?

Hey! You're thinking of Dot! Dot had a couple of movies. And yes! There was even one about saving the Whales.
YouTube - Dot and the Whale - Part 1 (http://www.youtube.com/watch?v=5r3FaMOzgeg)