1900 census of Rowan Co., Ky, Pearce precinct, enumerated 1 June, lists on p. 1B as family #11:
Oney, John, 49, b. Oct 1850, Ky Va Ky; Mary A., wife, 58, b. Apr 1842, Ky Ky Ky, married 22 years, 0 children, 0 living; Alfrey, Ellen, boarder, 50, b. May 1850, Ky Ky Ky, married, mother of 8 children, 8 living, nurse.

I do not know the identity of Ellen Alfrey. The only Ellen Alfrey I know of the right generation was the Ellen Reed married to Anderson Alfrey, but she is listed with her husband in 1900, recorded as the mother of 10 children, 5 living, born Jan 1847 (her death certificate says Aug 1848), so it does not seem like a very good fit.

1910 census of Rowan Co., Ky, Farmers precinct, enumerated 26 April, lists on p. 7B as family #120/128:
Oney, John, 59, b. Ky Va Ky, farmer; Mary A., wife, 63, b. Ky Ky Ky, first marriage for both, married 31 years, mother of 3 children, 3 living.

1920 census of Rowan Co., Ky, Pearcy precinct, enumerated 12 Jan, lists on p. 1B as family #22:
Oney, John, 70, farmer; Mary, wife, 74. Both born Ky Ky Ky.