Were those her book choices for fun or for class? I don't mind DD8 reading whatever she wants in that situation because i know the books she reads at night and in class are the right level. If DD wanted to read the whole Captain Underpants series again or revisit Junie B Jones it would be fine with me as long as it fosters her love of reading. Just be sure you help DD select appropriate late 3rd-early 4th grade level books for her to read too.

I got the reading bug from MAD magazines and comic books. Later fell in love with Shakespeare.

In our old school (a private gifted school) the teachers would tell parents to encourage any reading even below level reading for fun down time. They worked on comprehension and above grade level books in class. Also, I do agree that reading at the right comprehension level is important. We always used the 5-finger rule with DD. You open a book to a random page and while reading it count the words you don't know. If it's more than 5 you may not be ready for it. I think the librarian in that school taught us that.

Lastly, I have noticed that in the younger grades (K-3) in our old school (going by my experiences with DS10 who was the super early reader/very high reading level) they would read higher level books, do some vocab and move on. At our new school they do easier books (1-2 yrs above grade level) in class but do more in-depth studies. So, while DS did The Egypt Game in his 3rd grade reading class(a 6th gr level book) I am not too concerned when I saw it on a suggested list for his 5th grade. I know that if they do that book in class they will be learning study habits, active reading techniques, doing reports & presentations and more. So, it's not so much the book itself but what they do with it and I keep that all in mind with DD8 in 3rd grade.