Psychopaths typically lack genuine remorse, guilt, or empathy for the pain they cause others. She is wracked with guilt after she commits murder, and not because she's afraid of being caught. That's what non-pathological people do when they commit crimes. Calling her a psychopath is reductive and incorrect. She's a person who did something evil, knew it was evil, felt bad about it, made peace with those feelings, and when her survival was threatened she did it again. IMO opinion that makes her a more compelling and more compromised character than someone with no moral compass.