Her death certificate records Rosa T. Wallace, age 69 years 9 months 2 days, born 11 Aug 1886 in Rowan Co., Ky, died 15 June 1948 in Lick Fork, RowanCo., Ky, married, wife of Josh Wallace age 67, father Henry Gregory, mother’s maiden name Sallie Caudill, both born in Rowan Co., Ky, cause of death unknown, believed to be uremia due to suspected diabetes, informant Lula Gregory, Morehead, Ky, burial in Wallace Cemetery.

The year of birth may be incorrect; she was listed as age 15 born Aug 1884 in the 1900 census. But it does not conflict with the known birthdates of any of her siblings, and is consistent with the 1910 census, where she was listed as age 23. So the 1900 census might be the one which is incorrect. (Too bad the 1890 census was lost.)

I cannot find a marriage record for them in Rowan Co. The marriage date is estimated from the 1910 census.

1910 census of Rowan Co., Ky, Pearcy precinct, enumerated 12 April, lists on p. 3A as family #33/36:
Wallace, Josh S., 28, farmer, b. W.Va Va Va; Rosie F., wife, 23, married 8 years, mother of 4 children, 4 living; John H., son, 7; Sarah A., dau, 5; Lulie, dau, 2; Lutie F., dau, 6/12. All except Josh are listed as born Ky Ky Ky, although that makes the father’s place of birth wrong for the children.

The preceding household is Rosa’s parents, J. Henry and Sally (Caudill) Gregory, and the following household is Josh’s parents, Henry Timothy Wallace and Mary “Polly” Cline.