[theBCnut]

How old is she? She sounds like she is still going through that teenage lean stage and you should probably let her stay on the thin side, but it’s hard to tell from your post how skinny she really is. If you see 3 or less ribs, her weight is fine, same with back bones. Maybe look at the muscling in her back legs. Does she have a decent sized thigh muscle? If she is actually too thin, her muscling will suffer. If she is in good muscle, she isn’t too thin.