Elizabeth Cullen is Renesmee's twin sister. The one who was born a minute later and imprinted on by Seth. No one expected her but that didn't matter. They loved the twins equally but Renesmee's the good child and Elizabeth...not so much. Sometimes it's hard for Elizabeth not to feel less loved than her sister. But she still loves her family and they love her. The only real problems they're facing; 1. Elizabeth's wild streak. And 2. the Volturi want Elizabeth more than any of the other Cullens, partly for her powers and partly for something else. And they plan on getting her.