She also receives pain medication for her menses...so she feels pain. If she was as brain dead as they keep trying to convince people, midol wouldn't be needed.
So either way presents a winning argument in her favor. If she feels no pain, she's not suffering, so no need to take her out of her "misery." If she does feel pain, then she has some sensory perception, which is of course a sign of brain function. Then her state of life is not purely vegetative.