When Riley found a pile of ashes, indicating the death of another coven member, he exploded with rage in front of his subortinates, and attacked everybody in sight. Sara got half of one ear and some hair pulled out by him. She was able to reattach the ear, but not the hair.
She fought with another vampire in the war against the Cullens and killed him. Soon after, she got killed by the Cullens and the Quileute wolves.