If the mother has open cuts or gaping wounds from chewing it is probably time to see a vet as infection can set in rapidly and stitches may be needed. If you lose the mom you'll probably lose both the kits at this point. If they are just red and irritated it could help to rotate the kits giving one access at a time by putting one in a separate cage. This can be done every hour. Perhaps there isn't a good milk flow on that particular nipple. I hope someone who has experienced this before will respond soon. That is what I would do in this situation.
