[cypher]

It does look like a cut or scratch, hard to tell from the photo but it does also look as though it could be a bit inflamed which may mean it's infected, if it did get infected a trip to the vet would be essential if not then it may just heal up without treatment, if necessary it could be bathed with saline solution to keep it clean other than that nothing can be done without a vet, hopefully it will heal on it's own.
Get her to check her cage very carefully to see if there's anything that her ham could have caught itself on.