April Henry 
Girl Who Was Supposed to Die [PDF ebook] 

The only thing she knows is that she must run!When Cady wakes up, she has no memory of who she is. All she knows is that there is a pillowcase over her head and a person in the room has instructed someone to "take her out back and finish her off". Cady must find a way to save herself. But how can she when she doesn’t even know her name? April Henry has written another nail-biting suspense thriller, which explores such themes as murder, memory loss, identity theft and biological warfare. As in her previous novels, her strong female protagonist joins forces with another teenager. Together they race against time to stay alive and save Cady’s missing family.