According to Fairy Godmother, how did fairy tales come into our world? Chapter 24

Grandma (Fairy Godmother) explains that she happened upon their world when she was a young fairy and wanted to help others. Time passed and although she is the only one who can travel freely between the two worlds, she enlisted the aid of other people like Mother Goose to come with her to tell the stories, eventually telling them to people like Hans Christian Anderson and the Grimm brothers.