Look over her body to see if you see anything crawling around. Check your buns ears to see if you see anything crusty/scabby. If you see any of it then it would very likely be mites. It’s not severely life threatening, but you would need to get her checked out by the vet for antibiotics.
If you aren't seeing dandruff, crusting, lesions, or signs of skin irritation, dry skin could be possible though it's not a common thing in rabbits. I would keep an eye on it and if there seem to be signs of fur mites, treat accordingly with the proper antiparasitic(ivermectin or selamectin).