I'm not sure if Mary belongs to the same group of BLACK'S as our line but she very well could be. David b. 1782 and Sarah BLACK lived in Old Pendleton Dist, Pickens, SC then moved sometime in the 1830's? to Mt. Yonah, Habersham Co.(now White Co.), GA.Their children were:
James Osborne b. 1822 married Winny PAYNE, he died in the Civil War she moved on to Arkansas with their children
Samuel Sidney b.1826 SC married in Maury Co., TN to Sarah JACKSON then Sarah TINDELL, he died 1899 in Maury Co.
Mary B. b. 1834
David S. b. 1836 he married Margaret HALL/HALE in Maury Co. TN and he died there in 1912. In an 1860 White Co., GA census there was a Lorenzo Dow PENNY living amongst the Blacks. We have a copy of a letter from David Sr. to Samuel Sidney BLACK,Feb. 1851 in which he sends regards from his other children and names a John BLACK (brother to David Sr.?) and an "old Calley FARGIS" of whom we have no idea of his identity. Don't know if this helps but hope so.