Significance of Princess Penny Books?

Princess Penny books are representative of greed for Penny. Penny misses the stories her mother used to tell her, so she turns to the tree for stories. Penny does not always like the stories, but she does like some, and so keeps them hidden by her bedside. Penny, who is young and innocent, much prefers the stories Molly tells, and so increasingly turns away from the tree toward Molly through the novel.