That’s unfortunately normal in the kind of socially awkward rat cases. Its also a bit of a pain as you have a few choices to resolve it. You can try going back to smaller spaces (or stick her and those that dislike her in a very small carrier for a few hours to see if they get over it) but it quite often doesn’t resolve, as like you say in a small space they are fine. You can accept that shes going to get a few bites now and then, as long as they aren’t big or serious and shes happy in the group and eating well its fine. Or you could try her in another group if you have that option, especially if you’ve got a small group with patient older rats in it (this is something my friend who has a few girl groups has to do occasionally). In theory you could spay one or more of the rats involved, it can change some behaviours if theres a hormonal driver, but it doesn’t feel like its that serious to me, and probably more down to her being slightly scarred from her early life.
If she lived in a much smaller cage before it might be that the larger cage is adding to her social awkwardness. If you don’t have another group it might be that you can set up your cage in a way that gives her smaller sections to be in, whilst still giving the other rats space to explore.
To be honest if she seems unbothered and the wounds are tiny I would probably monitor it for a few weeks, probably with some time out for her and those that don’t like her in a small carrier.
