The Uninvited(2009)

A deadly battle of wills begins when Anna returns from a psychiatric facility and investigates the circumstances surrounding her mother's suspicious and untimely death. While Anna recuperates from the tragedy, her father becomes engaged to Rachel, her mother's former nurse, and moves her into their home. Anna's dismay quickly turns to horror when she is visited by her mother's ghost--crying out for revenge and pointing an accusing finger at Rachel. When her father refuses to heed their warnings, Anna and her sister, Alex, look into Rachel's questionable past. But Anna may be underestimating Rachel--perhaps fatally so.