Once she's calmed down and you can really see her paws, check to make sure she didn't cut them on anything. Check in your couch, make sure there aren't any loose threads, holes, or sharp objects hiding in the cushions. If she has ripped a toenail off, check and make sure there's nothing she could snag her nails on.
For either one, though, the treatment is pretty much the same. Keep her cage clean and keep an eye on her injured foot/feet. If you see any redness, swelling, or general irritation, you'll want to get her into the vet to be put on an antibiotic. Rats are amazing little healers, so as long as the cut doesn't get infected she should be just fine in a couple of days.
ETA : If ever one of your rats rips a nail again, you can place little mound of flour or cornstarch in a small bowl/plate and dip their foot into it to help clot the wound and stop the bleeding. The best thing is to check for major injury and then let them calm down since when frightened their blood pressure rises and it can take a while for the wound to clot.