Ida, a "fifth to eighth grade level" is actually just about perfect for a popular novel. In reading level classifications, level is based on education not age, so there's no such thing as an "adult" reading level - after twelfth grade level comes college level, where you'll find extremely difficult-to-read high literature and some textbooks.

Check out this link that Storm Machine found which talks about reading levels. I'm glad you brought this up. This will probably spark a good discussion, because I bet a lot of people are thinking the same way that you are.

http://www.amazon.com/forum/juvenile%20fiction/TxK4Y6Z3EMVZLJ?cdForum=Fx1TG90GI5...

Cheers,
Michelle