I was an avid and advanced reader, reading well above my grade level and during the summer if I hadn't had access to the entire library I would have been bored to tears. The librarian would suggest books but she never told me not to read one that I picked out. It was not a very big library and it didn't take me long to go through the entire library. I read many adult books and it did me no harm. I can't imagine limiting a kid who wants to read. How can they recognize the bad in books if they are never confronted with it? How can they find the joy in books unless they plow through some trash to get to the gems? Anything that keeps them reading is good, even if it's bad.