Wow...That's just sad. Yes, they probably will get the books "all out of order" and "dirty." Books can be replaced (and usually for free, because the child's parents would have to pay to replace them), and the benefits of your students being exposed to the books would be well worth it. Plus, it would be her job to teach the children how to use a shelf marker, and how to take care of the books. I would be irate if I were you!!!