I love when schools do that. I wish more schools did that. I think it's important to know about the books under attack. Hopefully the first book of flowers in the attic was before the brother started csa-ing his sister 😱 I would save that for a little older age.
I know I read that before 6th grade, probably 4th or 5th. I was already into Stephen King at that point as well. Moved on to Anne Rice in 6th/7th. The incest relationship starts in Flowers.
I remember knowing there were other Dollanganger books but i only read flowers in the attic and petals on the wind. Which I believe the brother and sister ended up back together (after the sister was in some other relationships)raising her kids by the end.