Why does big ma make Cassie apologize again?

Big Ma makes Cassie apologize again as a lesson in humility and the importance of respecting their elders. After Cassie confronts Mr. Barnett over the disrespect shown to her family, Big Ma feels that Cassie's actions could have serious repercussions. By insisting on the apology, Big Ma aims to instill values of dignity and resilience in Cassie while navigating the complexities of their societal context. This moment underscores the theme of respect within the family and community dynamics in the story.