It would be recluse. Nihilist means the belief that things are worthless. That could be an answer but it's probably not. An omnivore is a person who eats both vegetables and meat, so unless she was a carnivore (meat-eater) or a herbivore (veggie-eater), then it's probably not. Renegade is a person who something, and that could be it but she probably didn't lived alone as a renegade for the REST of her life. A recluse is a person who lives alone.
