What causes Cassie to break the dish at the beginning of chapter 4?

In chapter 4 of "Roll of Thunder, Hear My Cry," Cassie Logan breaks the dish out of frustration and anger stemming from her family's struggles and the injustices they face. The incident occurs during a moment of tension when she feels overwhelmed by her circumstances and the prejudice they encounter. The dish symbolizes the weight of her family's hardships and her own inability to control her emotions in that moment.