Survivor (The Floods Series #4)

The fourth book in Colin Thompson's brilliantly funny series about a family of witches and wizards—who might be living in your town
 
The youngest child in the Flood family, Betty, is a pretty little girl who looks quite normal—unlike some of her brothers and sisters. She goes to the normal elementary school down the road and she even has a normal best friend, Ffiona Hulbert. But Betty is not normal—she is a witch. When Bridie McTort, the school bully, starts throwing her weight around, Betty knows exactly what to do. And when Ffiona's dad gets bullied at work, Betty knows how to fix that, too. Meanwhile, her brother Winchflat has been watching old Frankenstein movies—and has decided he wants to build a human of his own.