Showing Evermore by Alyson Noël

Seventeen-year-old Ever is the sole survivor of a car crash that killed her entire family. Living with her aunt in Southern California, she's plagued by the ability to hear the thoughts of those around her, and haunted by the ghost of her little sister. She tries to tune everyone out, shunning her old lifestyle as the pretty, popular cheerleader, but somehow she can't hide from Damen, the new guy at school. Stunningly handsome, clever and not a little bit intimidating, there's something about him that doesn't quite add up. Ever realises he's hiding something, but nothing could prepare her for the truth - especially when the truth involves past lives, murderous enemies, everlasting love and the secret of eternal youth . . .