Who is Marya Alexandrovna from Great Short Works of Leo Tolstoy and what is their importance?

Marya Alexandrovna is the well-to-do wife of Sergey Mikhaylych who becomes bored in her marriage and then becomes uncomfortable around her husband. She then decides she is unhappy. She is also the narrator of the story, who confesses towards the end that her happiness increases when she learns to accept her husband and marriage.