Nancy Carlson 
Louanne Pig in The Perfect Family, 2nd Edition [PDF ebook] 

Louanne’s an only child. She thinks that it would be fun to have a big family, just like her neighbor George. He has five sisters and four brothers-the perfect size. When her parents have to leave town for the weekend, Louanne jumps at the chance to stay with George. But during her stay, there’s too much snoring, a long line for the bathroom, and absolutely nowhere to be alone. Maybe three is the perfect number after all!