The Ruining by Anna Collomore
Penguin Young Readers Group, 2013
From the publisher: “Annie Phillips is thrilled to leave her past behind and begin a shiny new life on Belvedere Island, as a nanny for the picture-perfect Cohen family. In no time at all, she falls in love with the Cohens, especially with Libby, the beautiful young matriarch of the family. Life is better than she ever imagined. She even finds romance with the boy next door.
All too soon cracks appear in Annie’s seemingly perfect world. She’s blamed for mistakes she doesn’t remember making. Her bedroom door comes unhinged, and she feels like she’s always being watched. Libby, who once felt like a big sister, is suddenly cold and unforgiving. As she struggles to keep up with the demands of her new life, Annie’s fear gives way to frightening hallucinations. Is she tumbling into madness, or is something sinister at play?”