There is genuinely no such thing as an inappropriate book for a child.
People in the tags who read Clan of the Cave Bear or Flowers in the Attic, but did you fucking die? You are fine like every other kid exposed to Jondalar’s turgid, upright member was fine. These are clearly ideal books for nine year olds because so many very alive and unharmed former nine year olds read the shit out of them and many adults find them boring.
Would you really be such a John Hughes adult kind of hypocrite as to rip the inspiring tale of Ayla, who invented aspirin, knitting and cunnilingus during the last ice age out of an elementary schooler’s hand?
If you don’t want kids to read a book, don’t allow it to portray a child’s actual, relateable anxieties around puberty, sex, adulthood and their parents in the most high gothic way possible. This is like preventing incest by locking your adolescent grandchildren in a small room with no access to non-family members.