In what ways does the Woman in the Purple Skirt remind the narrator of her sister? What is the narrator's relationship with her sister?

The Woman in the Purple Skirt reminds the narrator of her sister in the way she savors the last bite of her food. The narrator and her sister have not spoken for 20 years. She describes a fight they had years ago over the last bite of purin. The narrator still has a scar from that fight and assumes her sister must as well.