Power Play — Francine Pascal

Elizabeth and Jessica in a tug-of-war...

Chubby Robin Wilson has been following Jessica around for months. First she wanted to be her friend - now she wants to join Pi Beta Alpha, Sweet Valley High's snobby sorority.

When Elizabeth, Jessica's twin, nominates Robin for the sorority, Jessica is furious. Robin may be friendly and smart, but she's certainly not beautiful or popular enough to be a Pi Beta.
Jessica's determined to find a way to keep Robin out.

But Elizabeth is just as determined to make Robin a sorority sister. Soon the twins are locked in a struggle that develops into the biggest power play at Sweet Valley High...