Tisha Lopez believed firmly in life after death. Ancestors were as much family as her mother or her grandmother would be if they still lived. They still looked out for her, and she them- and all her own long dead family: simply because she couldn't see them doesn't mean they weren't there, guiding and protecting.
Her South American background probably accounted for her beliefs, she once told a friend. In her culture there was little difference between the living and the dead - on the one hand some were terrifying and could hurt you, and on the other were the dead.