What does Katie resent her brother Clean sweep?

In "Clean Sweep," Katie resents her brother for several reasons, primarily because she feels overshadowed by his achievements and the attention he receives from their parents. She believes he is favored and that his successes diminish her own accomplishments. This resentment is compounded by a sense of unfairness in their relationship, leading to tension and conflict between them. Ultimately, Katie's feelings reflect deeper themes of sibling rivalry and the struggle for recognition within a family dynamic.