[1] She was the sixth child of John Fielding and Rachel Ibbotson, who were active in the growing Methodist movement in the area.

Mary, John, and Mercy moved to Kirtland, Ohio, the following spring to join the larger body of the church.

Mary accepted the responsibility of caring for and raising Hyrum's children from his first marriage, including the future church patriarch John Smith.

[3]: 261 On September 21, 1852, Smith died in Salt Lake City, Utah Territory, at the home of her second husband, Heber C. Kimball, apparently of pneumonia.

Although she was widely known and respected during her lifetime, her son, Joseph F. Smith, further enhanced her reputation after her death as he presented her as a role model of courage and faithfulness in public addresses, sermons and articles.