Well you should really call the vet ASAP. How did it get swolen? A cut or a sports injury? If she hurt it through stressing it you should soak it in warm water twice a day with any anti-inflamatory stuff you find. If it's a wound you shoukd disinfect it and soak it in epsom salts. But no matter what injury it is you have to call the vet or this could be permanent.
