By virtue of simply being the antagonist to the story, I don't like Mary. But it has to be said that her ideas of "stopping the empire from making more bereaved families like hers" isn't simply born from the stupid childishness of her mind. It's easy for us in our times of peace today (though it may not apply everywhere) to simply sneer at her, but grown ass adults can easily conjure such ideas during such scenarios. Extremes situations like war easily exposes the fragility and weakness of the human psyche, and in their case, the war was brought to their recognition by the news of Col. Sue's death. There is no doubt that she IS naive and stupid borne out of inexperience, both in life and the realities of war. But her self-righteous tribalistic ideas are more than just hers.