But it was still a good movie.
In the book, Martha is of normal intelligence. Though she wasn't diagnosed there either, someone with her symptoms now would probably be considered autistic (or Asperger's before the DSM 5).
More importantly, in the book she was the victim of sexual assault by a group of her high school classmates. The boys lured her into the woods, saying the boy she had an obsessive crush on wanted to see her. The boys weren't convicted of anything, because "those fine boys have their whole life ahead of them, while Martha is a disturbed girl who probably brought it on herself." Worse, forevermore in her town there were nasty rumors about her, and nasty comments made to her about the night in the woods, in addition to the regular bullying she'd endured her entire life. She never received any therapy for her trauma, so in addition to her probable autism, she would have had PTSD.
So, for what happened at the end of the movie, Martha naturally assumed she was in danger and acted as she did in self defense.
In the book, Martha is of normal intelligence. Though she wasn't diagnosed there either, someone with her symptoms now would probably be considered autistic (or Asperger's before the DSM 5).
More importantly, in the book she was the victim of sexual assault by a group of her high school classmates. The boys lured her into the woods, saying the boy she had an obsessive crush on wanted to see her. The boys weren't convicted of anything, because "those fine boys have their whole life ahead of them, while Martha is a disturbed girl who probably brought it on herself." Worse, forevermore in her town there were nasty rumors about her, and nasty comments made to her about the night in the woods, in addition to the regular bullying she'd endured her entire life. She never received any therapy for her trauma, so in addition to her probable autism, she would have had PTSD.
So, for what happened at the end of the movie, Martha naturally assumed she was in danger and acted as she did in self defense.