Probably spoilers about her teacher
If someone was really deathly allergic to something, enough to have to carry an epi-pen, they'd have something like twenty all over the house. I have just plain allergies that I do immunotherapy for, and I have at least five around in my home, and that's not counting the two in my purse and the one in my work satchel. That whole bit was completely unrealistic; furthermore, I teach uni level, and she's a primary school teacher, but I also doubt anyone with any training at all would have let a lone student into their home when they were alone. It doesn't matter about the gender of the student, or what's going on, showing up at a teacher's home is weird behaviour; the teacher would have kept her out on the front porch, and might have still phoned a neighbour or something to be a third party present. There's just too much crazy crap going on these days to expose oneself to weird allegations from the student. And no, I'm hardly blowing it out of proportion, ask a teacher at any level, and if it hasn't happened to them personally, it's happened to someone they know.
In short, a totally dumb set of events.