I enjoyed these fantasy series as a pre-teen: Harry Potter (the best!!), The Chronicles of Narnia (C.S. Lewis), Fablehaven (Brandon Mull), Leven Thumps (Obert Skye), Artemis Fowl (Eoin Colfer), Percy Jackson (Rick Riordan), City of Ember (Jeanne Duprau) & A Door in the Woods series (James Dashner who also wrote Maze Runner) If she wants more princess-y books then Goose Girl & Princess Academy (Shannon Hale), Edenbrook (Julianne Donaldson), Ella Enchanted etc.