I have the following info and hope you have more to add.
Married at the residence of the brides' father, on the 19th December, by Rev. W. H. Dowling, under the same ceremony, Mr. Elijah O'Quinn and Miss Rebecca Beard, and Mr. Brooks All and Miss Ursula Beard. (between 1875-79)
(1876 - marriage to Lige O'QUINN Barnwell, SC; Becky b.c. 1856*)
Household: 1880 Elijah OQUIN Self M Male W 29 SC Farmer SC SC Rebecca OQUIN Wife M Female W 23 SC Keeping House SC SC Minnie OQUIN Dau S Female W 1 SC SC SC Source Information: Census Place: Broxson, Colleton, South Carolina
I am related to W.M.E. CAMPBELL & Elizabeth. Their dau. Annie Campbell m. Barnwell Preston BEARD. The dau. of Barney and Annie BEARD, Rebecca m. Elijah O'QUINN. And Ursula BEARD m. Brooks ALL. I am not sure how Ursula is related. She may have been the older sister that was not found on the 1860 Census or her first name may have been Ann, or she may have been a cousin.