Two stories:

My mom was in a religious school for a few years, and her craziest story was sex Ed, which was mandated in the state at the time. The entire class was "take this shoebox home." Literally no other instructions. The shoebox contained a mirror and nothing else. It was 20 years later before she realized what the mirror was for, because she wasn't informed it was a sex Ed class.

ETA: the school was mixed gender, the classes were not. Girls had separate classes from boys. The mirror was for standing over and seeing that you do, indeed, have a vagina, and then gaining absolutely other information

I was homeschooled, but not in a religious way. My mom ordered the books the state told her to order. When we got them they were fine, until we got to the science module and it told us how ancient humans and dinosaurs lived side by side. ... My mom immediately ordered different books.