After Charles has been rescued and the rest of the family has departed for England, Miss Pross confronts Madame Defarge, who had come to their lodgings to capture Lucie and her young daughter.
Miss Pross leaves Madame Defarge's body there and escapes with Jerry Cruncher, but the psychological shock and the sound of the gun cause her to go deaf.
Teresa Mangan has explored underlying similarities between Miss Pross and Madame Defarge: both women kill in the name of other women whom they love (Pross fights to save Lucie, whereas Defarge seeks revenge for crimes committed by Darnay's family against her dead sister).
At worst, she is that “woman of a certain age,” a spinster, the literary equivalent of a quirky and amusing character actor of theatre and later film.
Without the respectable, all-consuming outlet of loving Lucie, how like Madame Defarge Miss Pross might be.