These two kind girls are sunshine in Jane’s life. They are St. John’s sisters and Jane’s cousins. Diana and Mary Rivers are gentle, compassionate, educated young women who take to Jane immediately. Mary isn’t shown much in the novel, that’s why we can sum that she isn’t critical. Whereas Diana is a natural leader and teacher. She is passionate, kind, and reliable. Diana teaches German to teach both Jane and Mary and her firm insistence on Jane’s place in their household begins to push Jane and St. John together.
Diana and Mary Rivers in the Essays