This actually made me really happy, because until now I’ve been feeling like Lightning’s “question everything” mentality was simply forgotten after XIII. Lightning isn’t one to take things lying down, especially when it concerns herself or the people she loves. We especially see this in her interactions with Hope in XIII. After letting go of the more dangerous ideas he internalized from Lightning (including living for vengeance), Hope really does start to learn and grow in a positive way from her personal worldview.
This is really one of the first times ever in the XIII saga that we’ve seen the two sisters interact for more than a few seconds at a time, and yet Lightning immediately resumes the role of mentor to her little sister.