There is middle grade, childrens, ya, and adult. However, picture books are a very specific type of children's book. Someone looking for a picture book will NOT want anything else. It would be really useful to me to have this filter as a librarian and school teacher. I currently have almost 400 saved in a tag as jpic (Juvinile Picture Books). I know there should be more but I haven't gone though all my "childrens" books yet (a little over 300) to see which of those I should also tag as picture books.