How to Ditch Your Fairy by Justine Larbalestier (author) (US edition)

Everyone in New Avalon has a fairy. Though invisible, a personal fairy is vital to success. It might determine whether you pass a maths class or find the perfect outfit. But all fourteen-year-old Charlie’s fairy can do is find parking spaces – and she doesn’t even drive! It’s definitely time to trade up! So swapping fairies with her arch-enemy, Fiorenza, seems like a great idea. Fiorenza has an every-boy-will-like-you fairy – just what Charlie needs! But when Charlie gets her heart’s desire, she finds that the grass isn’t really greener on the other side. Now she’ll have to resort to extraordinary measures to ditch her new fairy, not to mention all her unwanted new admirers…