Reading diversly and widely has never harmed anyone.  If we want children to have global awareness, compassion for others, and the ability to think for themselves, then we should not restrict their access to materials.  

Trying to anticipate every sentisitve or objectional word, phrase, theme, or situation in a book is next to impossible.  What is offensive to me might not be to someone else, and vice-versa.  There is no way to accurately determine what in a book might be deemed sensitive or objectionable, so let's not even start going down this slippery slope to censorship.