What is the name of the children's book where a woman lives in a weeping willow tree and one day there's a flood and all of her animal friends have to come live with her?

The book is titled "Miss Twiggley's Tree" and it was written by Dorothea Warren Fox. The idea came to Dorothea one day during the autumn when she was looking out at an empty tree house her children had built during the summer. This wonderful children's book has recently been re-published by Purple House Press, and was even made into a short animated movie in 2000.