The more she argues, the more she might care. It's the woman who stops arguing you should worry about.
Conflict is engagement. Silence is the exit.
Why her fighting beats her calm:
You don't get in life what you want.
You get what you are.
Your discipline, your thoughts, your words, your house, your office, your books, your body, and what you produce already say who you are.
Therefore, fix what you are, for it becomes what you get in life.