Do you think Mrs. Miller is an unfit mother?

She would not win mother of the century nor is she completely unfit. I think your answer lies somewhere in-between. Daisy's mother, she is a model of America's loosely controlling mother figure. She is the opposite of a higher class European mother because she allows her daughter to know men she has not met and permits Daisy to do as she chooses. Mrs. Miller is timid meeting Winterbourne and openly admits that she is not able to persuade her son into going to bed but hopes her courier will do it. She agrees easily to Daisy's venture to Chillon with Winterbourne, although they would be alone. She allows Daisy to frolic with Roman society, inviting a snubbing from the Americans abroad. She often leaves Daisy alone with Giovanelli in their hotel room. However, when Daisy is ill, she proves herself to be efficient and composed and Winterbourne realizes that he did not give her enough credit.