Gertrude is describing how the Negroes of Maycomb are upset over the outcome of Tom Robinson’s trial.
At the missionary circle meeting of ladies in the Finch house, Helen Robinson’s situation is a point of discussion. Gertrude seems to believe that everything will “blow over,” and when Scout asks her what she is talking about she goes on to describe how the “the cooks and field hands are just dissatisfied” and “grumbled” after the trial.
"Gertrude, I tell you there's nothing more distracting than a sulky darky. Their mouths go down to here. Just ruins your day to have one of 'em in the kitchen. (ch 24)
Gertrude does not care that Tom Robinson was wrongly convicted. She does not see Negroes as people. She treats them like children, and considers them children. When her cook was upset, she told her she wasn’t acting Christian. This is completely hypocritical, of course, because Gertrude was not at all worried about Helen or her family, or Tom. Tom did nothing, and was still convicted—all because no one could take a black man’s word over a white woman’s.
Mrs. Merrkweather uses the racial slur "sulky darky" to describe the attitude of one of her African American maids. After the conviction of Tom Robinson, the entire African American community of Maycomb is upset. During Aunt Alexandra's missionary circle, Mrs. Merriweather begins to discuss with Gertrude how her African American maid, Sophy, acted disappointed and was silent while she worked following the Tom Robinson trial. She refers to Sophy as "darky" which is a racist term to call an African American person. Referring to Sophy as a "sulky darky" illuminates Mrs. Merriweather's racial prejudice; she does not have sympathy for her African American maids and, like the majority of Maycomb citizens, is a racist. Mrs. Merriweather proceeds to explain to Gertrude how she told Sophy that she was not acting like a Christian following the Tom Robinson trial.