In an attempt not to single anyone specifically out.

[She takes a step into the room and picks up a book that's nearby, turning it over in her hand.]

You enjoy reading? Perhaps we should get you more bookshelves so it's easier for you to keep more of them. [She's still looking at the book even as her smile grows a little wider.] And boy's rooms are meant to be a bit messy - if you fear for that small bit in the left corner, it isn't necessary.