Nightmare Fuel / Baby Teeth

• Hanna is a seven-year-old girl who is clearly developing ASPD or something similar. She hates everyone for no apparent reason, especially her mother Suzette, whose life she has deliberately been making miserable ever since she was a toddler. Her inner monologues reveal that she constantly thinks about hurting and killing other people. Really, the only difference between her and Kevin from We Need to Talk About Kevin is that she hasn't committed a school shooting yet...and she very well could be on her way to doing that, give or take a few years.
• Hanna gets jealous of a girl named Aria in her kindergarten class with beautiful blonde hair and imagines flaying her scalp off and wearing her hair as a wig. When she tricks Aria into drinking water mixed with red paint and the girl gags and chokes on it, she smiles at the blood-like liquid pouring from Aria's mouth and imagines tricking her into drinking crushed glass instead.
• Hanna's inner thoughts as she watches some of her classmates at play.
  Playing outside wasn't much better. Everyone ran around the playground shrieking in a way that pained her ears. A pair of do-goody best friends in matching floppy braids played with striped jump ropes. Hopping. Skipping. Getting their feet tangled up. Laughing. Hanna thought it would be a much better game if she could tie the rope around one of their necks. And then maybe she—would any other children help?—could drag her along like a pull toy and watch her wriggle and scream. That would be fun.
• Hanna tampers with the pills that her mother takes for her Crohn's disease, emptying out the capsules and filling them with flour. As a result, Suzette becomes increasingly ill and has no idea why. She only finds out after Hanna has been sent away to boarding school, when she discovers half an empty capsule in the flour bag.
• Hanna's plan to kill her mother involves putting a bunch of thumbtacks sharp side up on the floor beside her bed so Suzette steps on them, and then coming into the bedroom and beating her to death with a hammer.