What is the problem everyone has with her age? She is fine. I can tell you from memory that, at least as far as words and actions go, she is a perfectly normal girl. The males should even be openly sexuallizing the teacher.
I am not saying I get it, at that age I could not for the life of me understand the appeal of the grannies. I thought they were all insane.
If your worried because her attacks seem to work on the teacher, I won't try to convince you not to be creeped out by it. But, I can reason it into normality. Teach is in love, and has always been in love, with her childhood frind from school. She has spent the last XX years living off of memories of her and her friend whom she loves in school. Her entire fictional love life is based off of those memories and fantasies around them. In other words, she spent XX years imagining herself (as a jk/js) with the version of her friend which was a jk/js girl. Her fantasy is basically becoming reality now, except... she is old af.