Polly's Running Away Book by Frances Thomas
Polly is not happy. Her mother is pregnant and can't stop talking about the 'new baby'. Her little sister is exceptionally annoying. Her hamster has gone missing. And she is no longer friends with her best friend! So Polly decides that her only choice is to run away from home. A witty, lively and fun-filled novel in diary format, brilliantly illustrated throughout by acclaimed Sally Gardner.