If it's from an injury and not something else, I think she should be just fine. Both of my boys have had paw injuries at some point (usually scratches from each other) and they usually look pretty bad at first but within a day or two, you'd never even know anything happened. Degus seems almost surreal with the way they heal sometimes. As long as it's not bothering her or it doesn't look infected, I think she should be fine
I'm certainly not an expert though so I would just use your judgement. I'm not sure about the fur growing back, my boys have only lost a little bit of fur at a time and it has always grown back.