If your aunt does not want the vaccine, then she should be be ready to respond quickly to any initial symptoms, should they develop.
Vitamin D, Zinc, vitamin C; at the bare minimum.
Ivermectin, although a prescription drug seems to be reasonably easy to get (some have purchased veterinary versions from Amazon, just in case). It is not expensive. Ivermectin seems effective as both prevention and treatment.
She knows. I have the horse paste. She listens to me after I cured her of an infected hair follicle.
She has rarely had a cold in her life, so I’m not too worried.