Whats wrong with her?

The obvious assumption is that the bit did the damage. but until you have her examined by your vet, you don't know that. There are other possible or even probable causes for bleeding of mouth tissues, and some involve exposure to toxins, or dental infections or other issues. only a direct exam by a vet will give you the diagnosis, so that is what is needed. in the meantime, watch what sheis eating and how she is handling her feed, and be sure she has plenty of cool, fresh water to drink 24/7.