I can't think of the movie title...?

It was a cartoon movie. All I remember is there is a little girl. And I believe she is in foster care, because both of her parents died. She hangs on to this memory about a house on the lake, and she goes there with her animals. The person she lived with kept them in cages, and she escapes. I remember her being on a ferry or some boat for quite some time, and there was a Ferris Wheel. And she has a letter from her father. I wish I could be less vague, but I can't seem to remember anything else....