What term best describes Mrs Joe from Great Expectations?

She had been struck in the head by Orlick's hammer, which had probably caused brain damage. She loses the ability to speak (ironically, many people did not like her short temper and constant rambling), so she becomes dependent on Biddy and Joe to take care of her. At one point she panics when Orlick is in the room, which is somewhat strange. She ultimately dies from the injury while Pip is in London.