At age 7, illustrations can be a good thing if the content is more advanced. You may want to ask your favorite librarian (or look over some of these lists) for books at the right levels that also contain some illustrations.
I would be really bummed if my DD7 didn't want to read some of the picture books we read. I mean, think of Patricia Polacco books -- they are really thoughtful, beautiful books with valuable messages (which anyone with 2E kids might appreciate a few of those, like the Art of Miss Chew, Junkyard Wonders, and Thank You, Mr Falker), that you'd miss out on if you only read text. :-)
We love the "You Wouldn't Want to be..." series, too -- history with pictures. And the increasing availability of younger audience graphic novels out there are a huge draw to both my kids. Plus, even my DS9, who reads things like Harry Potter, still will read thru Geronimo Stilton books, just for fun (though he prefers the Kingdom of Fantasy over the shorter ones).
