1860 U.S. Census, Northumberland County, Virginia
Union Village Post Office, Page 24
Dwelling 183, Family 185
Sandford, Wm. S., 35, male, miller, value of personal estate $50, born in Westmoreland County, cannot read or write
Sandford, Mary, 35, female, born in Westmoreland County
Sandford, Susan H., 10, female, born in Westmoreland County
Sandford, Ella V., 8, female, born in Westmoreland County
Sandford, John Wm., 4, male, born in Westmoreland County
Sandford, Mary E., 2, female, born in Northumberland County

1870 U.S. Census, Westmoreland County, Virginia
Nominy Grove Post Office, Page 12
Dwelling 91, Family 91
Belton, Saml, 25, male, white, farmer, born in Virginia, cannot read or write
Belton, Susan, 20, female, white, keeping house, born in Virginia
Belton, William H., 8/12, male, white, born in Virginia, born in September
Sandford, Mary, 42, female, white, at home, born in Virginia, cannot write
Sandford, John W., 13, male, white, labourer, born in Virginia, cannot read or write
Sandford, Ella, 15, female, white, at home, born in Virginia, cannot read or write
Sandford, Mary E., 9, female, white, at home born in Virginia

Samuel Grayson Davis married Mary Elizabeth Sanford in Westmoreland County, Virginia on 22 February 1877. He was 21, single, born in Westmoreland County and living there, a farmer. She was 18, born in Northumberland County, Virginia, and living in Westmoreland County. The parents were Jos. W. S. [sic] and Ann E. Davis, and Wm. & Mary? B. Sanford. [Westmoreland County, Virginia, Register of Marriages 1853, p. 69.]

1880 U.S. Census, Westmoreland County, Virginia
Supervisor’s District 1, Enumeration District 115, Page 73 or 463
Cople District
Dwelling 912, Family 912
Davis, Grayson, white, male, 25, married, farm laborer, born in Virginia, both parents born in Virginia
Davis, Bettie, white, female, 21, wife, married, keeping house, born in Virginia, both parents born in Virginia
Sandford, Mary, white, female, 50, mother, widowed, at home, born in Virginia, both parents born in Virginia
Sandford, Ella, white, female, 26, sister, single, at home, born in Virginia, both parents born in Virginia
Bolison, Bob, white, male, 6, single, servant, born in Virginia, both parents born in Virginia

She is listed as the wife of S. Grayson Davis in his death record.