Who is Mama from Wideacre and what is their importance?

Beatrice's mother, Mama, did not choose her husband and the two are not well suited. Beatrice believes that her mother might have been a different person had she married someone else. Mama is aware that there is something evil between Beatrice and Harry, and she senses that Julia is actually Beatrice's child, not Celia's. When she is confronted with Beatrice and Harry coupling on the floor of the study, however, she has an episode with her heart. Beatrice, leaving Celia to care for Mama during the night, relays incorrect medicating directions and Celia inadvertently causes Mama's death, a mistake Beatrice lays on John.