Middle School : My Brother is a Big Fat Lair by James Patterson

Being Rafe Khatchadorian's little sister isn't easy...
 
Rafe broke school rules for fun. Rafe's report card never saw an A. Rafe made a million enemies in school. 
 
And now everyone thinks I'm just like him! So I'm going to prove them wrong.
 
It's time for some serious payback. 
 
Suitabel for ages 11+