The Wife Upstairs by Freida McFadden

Victoria Barnett has it all. A great career as a nurse practitioner. A handsome and loving husband. A beautiful home in the suburbs and a plan to fill it with children. Life is perfect—or so it seems. Then she’s in a terrible accident… and her life is forever changed. Sylvia Robinson is hired as a caregiver for Victoria. Sylvia moves into a spare room, feeds Victoria, and takes her on long walks. The two women become friends. But as it turns out, this simple nursing job is more than what it seems. As Sylvia and Victoria's friendship grows, Sylvia realizes that Victoria is desperately trying to tell her something. If only she could speak.