This does not add much to the discussion regarding Dr. Bethune and his family, but it does document their
residence in 1860 as Dale County, Alabama.

I transcribed these from images of the 1860 U. S. Census, Dale County, Alabama:

Page 24—522.gif
P. O. Newton—6th July 1860
164/164
John G. Bethune, 49, m, Farmer, $2200 R/E, $9000 P/E, Ga.
Patince [sic], 49, f, Ga.
Mary, 19, f, Ga.
Martin, 21, m, Farm Laborer, Ga.
Elizabeth, 17, f, Ga.
John, 15, m, Farm Laborer, Ga.
James T. (? or Y.?), 13, m, Ga.
Sarah 11, f, Ga.

John, James, and Sarah attended school.

http://freepages.genealogy.rootsweb.com/~jmg12/Census/1860%20Dale%20Co.,%20AL/522.gif

Page 107—605.gif
P. O. Newton—6th August 1860
739/739
Wm. C. Bethune, 27, m, Physician, _____R/E, $1000 P/E, GA

Dr. Bethune was apparently living by himself. Some of his neighbors were

731. Martin Bryan, 28, m, Farm Laborer, Ala.
732. Israel Parker, 62, m, Farmer, Va.
733. Wm. Whitman, 50, m, Farmer, NC
734. Burrell Blackman, 71, m, Farmer, SC
735. Green W. Blackman, 40, m, Farmer, SC
736. Noel Dowling, 50, m, Farmer, SC
737. A. I. (or J.?) Sellers, 22, m, Farm Laborer, GA
738. John C. Hudson, 53, m, Farmer, NC

http://freepages.genealogy.rootsweb.com/~jmg12/Census/1860%20Dale%20Co.,%20AL/605.gif

If John G. Bethune and wife are Dr. Bethune's parents as previously indicated, then it would appear the gap between Dr. Bethune's age of 27 and Martin's age of 21 would suggest at least two additional children elsewhere or deceased.

Hope this helps in some way.

Margaret