A s I ' v e s a i d b e f o r e , she isn't actually sexually attracted to teenagers, she just imagines that the boys she flirts with are her former classmates and she takes pleasure in getting compliments about her appearance from them, since they bullied her about her unattractive looks when she was younger. If this is the case than the poor woman isn't right in the head. Maybe her befriend elimination could involve making her stop trying to get revenge on her bullies by romancing male students and trying hard to get envied by female students. It's important to note that Mida doesn't exist so people shouldn't make a fuss over her behavior.

She seduced 69 boys because she imagined that they were her former bullies now drooling before her instead of shaming her like they used to.

with her suitor being 16

I think you are referring to Hazu Kashibuchi, but even if you were talking about someone else, I'm pretty sure they aren't canonical 16 since, according to YandereDev, "The students who are currently in their third year started attending Akademi when they were 16; now they are 18. The students who are currently in their second year started attending Akademi when they were 17; now they are 18."