Adult content for children

I am the father of a 14 year old and a 7 year old, also a step-father of a 24 year old. As a parent, I believe that there is certain material that should be kept from children til a certain age like anything pertaining to sex I would not let my child read until they were at least 16 years or older. I am very old fashioned and am protective of what my kids do and who they see because the world has become an ugly place and I don't think there is such a thing as being too protective of your children. I do let my 14 year old read such books as the Twilight series and know by watching the movies that there are sexual themes in the books, but as for anything else of the such I don't let her  read it. I'm sure she reads stuff that she don't tell us about because we cannot screen everything that she reads but I try to encourage her to read things that are written for her age group.