Help With Tank Divider

[WDW Donna]

I have two females in a divided tank. My problem is that I think the divider slats are just big enough that when Lilo gets close enough to the divider Poly beats her up. I have twice now found wounds on Lilo that look like a fight. I can't see any way she could have aquired these wounds on her side of the tank.
Anyway. My husband suggested putting nylons over the divider. That way the water can get through, but Poly's big mouth can't. The nylons couldn't hurt the fish in any way could it?
Also, what (if anything) can I do for Lilo. She looks like she has a bite out of the base of her tail. Should I QT her? Is there any kind of medicine that will help the healing?
thanks