"Orphan" Movie (contains spoilers)

Last night I went to see "Orphan" with my friend. I give the movie about a 7 for Scary-factor, and maybe even a 9 for plot and here's why: I went to this movie "knowing" that I was going to see one of those demon-child movies, which are pretty disturbing in general. However, I was plesantly surprised by the truth of the matter revealed toward the end of the movie. Instead of a demon-child on our hands who never got love, we have a 33-year old psychotic who just happens to have a rare hormone disorder than makes her look very young. She poses as a little girl, and being the master maniupulator she is, attempts to seduce the father of each family she infiltrates. Come to find out she is one of the most violent and dangerous inmates of a mental hospital from which she escaped. I wonder where they got such a story. The truth that I don't want to admit is that they probably got it from some real-life case from the 1930s or something...or maybe several different cases rolled into one. I should look it up.