Here's some references I dug up. I've also read anecdotal reports about little girls and boys as young as 5 pointing at a sex education book (one that was banned in Florida) saying "my dad does this to me", here's one I was able to find: https://bookriot.com/sex-ed-books-protect-kids/ (ctrl-f This is me)

https://www.theguardian.com/education/2015/apr/16/sexual-abu...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6283686/

https://info.primarycare.hms.harvard.edu/review/sexual-educa...

Even China started pushing comprehensive sex education nationwide due to high rates of rural child sex abuse: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9406756/