I would suggest just keeping her on clean paper towels, changing them out whenever they are soiled. Keep an eye on the spot to be sure it is not spreading. As long as she is eating regularly, I wouldn't worry until she sheds. Hopefully then it will improve, if not just go from there. If your friend thinks it is the beginning of scale rot, just be sure the paper towels in her enclosure are kept dry (while maintaining proper relative huidity).