When I was in middle school (40 years ago) most of my teachers were middle-aged men. The one female teacher we had was also middle-aged, in her 40s or 50s I think (she seemed as old as my parents, maybe slightly older). In the school district I attended at least, the young female teachers were assigned to the young kids, Kindergarten through third grade. Did we simply know better back then?
When I was a freshman at a Catholic high school, the chemistry teacher was a very young and pretty nun. I can't remember her name. Didn't take chemistry and only saw her here and there since her classes were on the fourth floor while most of my classes were on the first floor.
The next year, my soph year, I didn't see her around. I asked a few other students where Sister X was. They said, "oh, didn't you hear...she ran off with the chemistry supply salesman."
Apparently they both had the right chemistry for each other.