This morning I took the book that concerned me back to the librarian at my daughter's school and gently pointed out the passages that worried me. She apologized, telling me she'd never read this book, and that she'd simply sent OK looking for books by this author, not this particular book. She told me OK has been reading a lot of "bubblegum books," specifically Goosebumps, and that since she read one every day, she thought she could handle better books. I explained that OK hasn't been allowed to read Goosebumps up till now, which is why she's gorging on them, but that she reads a lot of good books, too, so not to worry about expanding her horizons. Anyway, the librarian agreed that this particular book should be marked with a red dot, which means it can only be checked out to eighth graders. Which seems reasonable to me.
The interesting thing, though, is that this entirely reasonable approach on the part of my daughter's school is the exact same approach that another parent asked for in another school system... thus earning the book the "banned" label.