2) The second chapter is called "Warpath of Suck"
3) I can't imagine any high schoolers calling a teacher "Miss Ann Thrope"
If you aren't convinced, please see points 1 and 2 and reread until you get it. Girl-on-girl hate (even if it's in the guise of a teehee text from a big sister) is not acceptable. Don't talk about "the warpath," ever. It's not a thing. It invokes the popular image of Native people as bloodthirsty and war-loving. Do not do this. See also: "low man on the totem pole" and sitting "Indian style."
I received an ARC of this title from Netgalley. Grr.