If she has an ear infection, that could affect her balance. Rooster damage could be possible. We are not vets, but can only guide you with possibilities. The oxytetracycline Can help if it is respiratory.
Does she have any gunk or bubbles in the eye? Could she have been pecked in the ear? I would check inside the ear canal with a QTip for mites or gunk. Let us know what you find. She might have a respiratory infection or ear infection. Do you have any antibiotics, or can you see a vet? You can...