What evidence shows us that Mrs.Merriweather is a racist in Chapter Twenty-four

Mrs.Merriweather is complaining about Negros being  "sulky darky" after the trial of Tom Robinson,

"Now far be it from me to say who, but some of 'em in this town thought they were doing the right thing a while back, but all they did was stir 'em up."  (Chapter 24)

Miss. Maudie, however, will have none of her racism at tea time.