The Enchanted Island of Yew

The Enchanted Island of Yew (1903) is a children's fantasy novel.  Sesely and two companions are enjoying a picnic in a Forest when they are accosted by a fairy.  The fairy pleads with the girls to be changed into a mortal.  The girls agree to transform the fairy into a human boy for the space of one year.  Prince Marvel, the naive ex-fairy faces many challenges, including a fiery dragon.