I recently received all of Mary Card Yarnell's very extensive research on the Newbern family.
I looked up Hickman Newbern, and this is what she has:
Hickman, born 1800-1810 (20-30 in 1830)
Married 22 December 1825, Lucy Luck, Jackson Co., GA (born 1800-1810, 20-30 in 1830)
Children:daughter, 1825-1830 (possibly Sarah Ann who miarred Wiley Roberts, 1846, Fulton Co., GA)
Daughter, born 1825-1830, possibly Malinda, who married Alen Blair, 1850, Fulton Co., GA
Nancy E., born ca. 1830, Campbell Co., (GA) prob. Married 3 Dec. 1855 Fulton Co., GA to Alfred Driggers
Joshua Lewis, born 1833, ditto.
Mary J., born 1836, prob the one who married 23 Dec 1853, Fulton Co., GA, Wesley Collins.
John L. born 1838
Thomas J., born 1840
William J., born 1843
Martha, born 1847.
Added data from Dale E. Newburn, Overland Park Kansas, via Judy Watson to Arlene Jirovsky.
Sources: 37,000 Early Georgia Marriages, Maddox & Carter 1975. Drawn from "Georgia Pioneers," a quarterly genealogical magazine published by Mary Carter of Albany, GA.
1830 index to Ga., census, Hickman Newbern, p. 344 of Jackson Co., GA
1850 census index, Ga: Hickmon Newborn, p. 442, of Campbell Co.
She also has a separate card that lists:
Hickmon Newborn, born ca. 1802, NC
Married Lucy, born ca. 1805, Va
She lists the same children, and states that her information came from the 1850 census for Campbell Co., GA, p. 443, #568-568.
Hickmon Newborn, 48, farmer, born NC
Lucy, 45, born VA
Nancy E., 20, Ga
Joshua L. 17, farmer, born Ga
Mary J., 14, GA
John, 12, GA
Thomas J., 10, GA
William J., 7, GA
Martha, 3, GA
There's an entry for a Nancy Newbern, who is listed in the 1820 census for Georgia in Madison County.
If you can give me details as to the "Brother John" that you refer to in your posting, I can try to look him up.