If she finds a hole that she can just slightly get her nose through she will rub on it and hurt herself that way. I have one tub in my rack that has a slightly bigger gap up top, about half the thickness of a pencil, but my sub adult female still managed to rub her nose raw on it. I would be worried that with enough rubbing/pushing she could make the hole large enough to fit through. What about getting a new screen and hot gluing it over the hole?