How does Bernice change over the course of the short-story, Witness?

Bernice is a high school guidance counselor who lives in Brooklyn. Early on in the story, Bernice tells Silas about how she was approached by a singing man on the street and how she agreed to go out with him. This man eventually becomes her husband, of whom Silas does not approve. Bernice, too, struggles in her relationship with Dove: she is notably anxious when he is at work, but notably frustrated when he is home. Bernice also experiences a physical and mental decline over the course of the story, preferring to study the histories of African countries and consult her healing crystals instead of going to work. At the end of the story, Bernice has a stroke and dies, an event that throws her brother's interpretation of her life into question.