Whether she is an empowered wife or not, Juana certainly acts from good motives throughout the novel. When you think about it, submission is a very necessary part of the experience of every human being, not for wives only. Students submit to teachers, teachers to school administrators, school administrators to the school board, the school board to the community, and so on. I think you are also noticing that love for spouse and offspring is a motivating factor. Characters in novels, short stories, plays, movies, and even in jokes, do what they do for at least one good reason.
Every author has a viewpoint and, hopefully, a message.
He has to keep the message as simple as he can, even if he dresses it up with a lot of detail and suspense or whatever. That is why even though art imitates life, it never quite captures real life. But, it can and does help explain the issues of life. Whether he finds it or not, hopefully he writes and speaks about it, and thus adds to the inventory of human imagination and knowledge.