Who is Mathilde from The Masterpiece and what is their importance?

Mathilde is a somewhat repulsive woman, reeks of the herbs and spices sold in her husband's shop. Unfulfilled in her marriage, Mathilde takes multiple lovers. After her husband's death, Mathilde finds religion, something believed to be a ploy to distract the locals from gossiping about her affairs. Mathilde later married Jory, masking her past with an air of respectability.