Don't you love it when someone who doesn't sew gives you an assignment?
I think I would go in a different direction. No, I don't mean run away - I mean a different direction with the pockets. I would make individual pockets, not connected to each other, and then they could be hung with clothespins to a line. That way if one gets ruined, the whole thing isn't lost. And you can always add another, or subtract one, or hang some in one part of the room and others in another part. You could even send them home with the kids at the end of the term and YOU could make another set for next school year. (Or maybe teach your daughter to sew?)