In the story, who is described to have the hardest mouth in their town, and why was this person described this way?

Monka, Esi's daughter and Ato's sister, is 'the sauciest girl', and she has 'the hardest mouth in this town'. Monka is a modern girl, who doesn't adhere to tradition. "The hardest" mouth refers to the way she treats people, she is independent, refuses to be subservient, and is seen as rebellious.