Looking for an old children's movie?
The movie I'm looking for is about an adventure of two small kids. The oldest is a boy whose little sister rosy(I think that's her name) is annoying. They go to a river that's by a bridge where the boy tries to play with his boat and meanwhile his sister is under the bridge and drops her dolly through a hole. She falls through the hole and her brother than noticed she gone and soon goes through the hole trying to find her where they meet this funny loving creature which soon they get into trouble, and their thumbs turn green and purple.
