Hi! My friend Nix was texting me and told me your idea for a backstory! I had created one, but it didn't go back as far as yours. They actually fit together quite nicely, I think. I had the idea that the "she" in Anita's chapter was a roommate, who died trying to protect Anita. We created this idea of the roommate, Claire, being a disgraced daughter of Apollo. She had the gift of prophecy, but because she didn't look like her siblings, nobody believed her. She fled to the mortal world, and her gift told her to protect Anita at all costs, so she took a fatal blow from a monster. While she was bleeding out and fighting monsters, she told Anita to "RUN!" And so Anita did.
And your idea went even deeper than mine. Do you like it? I think it works together quite well.
