Plot story line ideas

The plot for our horror film is going to be an 8 year old girl that moves into a new house with her family, she finds a doll in the attic of the new house, which she becomes obsessed with the doll. She begins to communicate with the doll, and it overpowers her and she becomes possessed by the doll.

Later on, the girl hears voices telling her to kill her friends/family. Certain objects remind her of past memories.  She ends up killing the victims and everything becomes so traumatic.  We will have the idea that she is about to kill someone but this won't be presented as it will give away the story line too much.