Lucille prioritizes the things she loves most, which means her brother and their family home. She takes great pleasure in asserting herself, and in rubbing her mother’s nose in their misdeeds (“It comforts me to think she can see all that we do”). Unfortunately, this also means Lucille’s morality differs from the people around her, in bad ways. She hates her mother, so she murders her; she hated her father, so she killed him too. She stood in and took “beatings” for her brother, and developed a sexual fetish for him in the process. She also has an irrational clinging to her childhood home, which is not beneficial in the long term. Despite its crumbling foundations, rotten floorboards, and broken ceiling, she and Thomas continue to stay there, murder women for their money, and pour their finances into a place they ought to just burn down and abandon. Her motives are purely financial for all she does, achieving tangible results (an income she cannot earn any other way).