While the family of Madame DeFarge was brutally killed by aristocrats when she was young, Marie DeFarge seeks revenge to the point of becoming a robot of vengeance, seeking redress against an entire class of Frenchmen. She even believes herself to be an elemental power, unstoppable as a tornado,
Then tell the wind and fire where to stop, but don't tell me.
It is, indeed, apparent that Madame DeFarge commits the sin of what Aristotle termed hubris, unnatural pride. Ironically, she becomes aloof, cold, and cruel--like the class whom she detests with her blood thirst represents that of the French Revolution. Like those of this revolution, Madame DeFarge is cunning and extremely cruel as she seeks to punish an innocent member of the Evremonde family. These actions of Madame DeFarge are unconscionable.