This is a book for younger children, ages 6-9 or even younger, if read aloud. This was one of my favorite books as a child. I still love the story of the escaped crabs and the story about the boys painting their bedroom floor without their mom and dad.
Some criticize this story as making too light of adoption and portraying family life with an adopted child unrealistically. As a child who grew up with adopted siblings, I think it's simply a child's viewpoint and not unrealistic.