The movie starts with a father picking up his daughter from a mental asylum, and returning to their home situated near a river. The film focuses on four characters mainly, father, a step-mother, sister and the main protagonist. Her mother died long before and she used to cry before the photo.
The climax is, she kills the step-mother along with her younger sister, and confesses to her father. Then her father tells her that her sister died a year ago. Then she realizes that it was an illusion. She killed the step-mother herself and the movie ends on taking her back to the mental asylum.
English Hollywood Movie. I assume the release date might be between 2005-2012.