How To Get What You Want by Peony Pinker

Everyone in Peony Pinker's family wants something. Her dad,
a sports reporter on the local paper, wants to get out of doing the problem
page while the agony aunt is missing; her mum wants to stop working at the
garden centre where all the plants keep dying; and her big sister
Primrose wants to be called Annabel. What Peony wants most in the world - even
more than she wants a dog - is to stop Primrose's nasty new best friend Bianca
from being horrible to her. When Mr Kaminski next door
tells them the secret of how to get what you want, Peony decides it's time to
put a stop to Bianca at last. But can she get what she really wants?