Courage's silent daughter, Kattrin distinguishes herself as the character who most obviously suffers from the traumas of war. She wears these traumas on her body, since the war robs her of her voice as a child and later leaves her disfigured. Throughout most of the play, she figures as the war's helpless witness, unable to save her brother Eilif from recruitment or Swiss Cheese from the Catholic spies. Later, she will stand by Courage when she refuses to identify Swiss Cheese's body. As Courage continually notes, Kattrin suffers the virtues of kindness and pity, remaining unable to brook the loss of life around her. This kindness manifests itself in particular with regard to children, Kattrin's maternal impulses perhaps standing against Courage's relentless dealing and her resulting failure to protect her children. Ultimately Kattrin will "speak," sacrificing herself to save the children of Halle, and it is appropriate that the play implicitly compares her to the martyr Saint Martin.

The war in particular impinges on Kattrin's sexuality. As Courage notes, she is ever in danger of becoming a "whore"—that is, a victim of rape—and thus must lie low and wait for peacetime before considering marriage. Privately Kattrin will "play the whore" in a sense in her masquerade as Yvette, the camp prostitute, in a bid for sexual recognition. Notably, her disfigurement will ultimately make her marriage impossible.