I see it going sort of like this. She keeps Chris enslaved till he finally passes at age 60 or so, at which point she sort of crashes into dark, eldritch slumber. Eventually as the bills go unpaid, within a few years she'll end up evicted, living out of her van with only a portable mini-hoard to snuggle into. Once the gas and pocket money runs out, I figure she might crash into slumber again - and there she would stay until a lifeform capable of serving her evolves from the hoard. And since she has no need for food, drink, or medicine, "serving" means only "spooning".