--From The Marvelous Land of Oz--
The main character of the story is a boy named Tip, who is really a girl magically trapped in a boy's body. Tip doesn't even think he is a girl, but agrees to be turned into one at the end of the story.
There is also another character who has been calling Tip "father" throughout the story and expresses some confusion before the sex change occurs, but immediately accepts it once it has been completed.
Just a typical children's book.