The children of the younger daughter of Richard Keith Call and "Mary Call I", "Mary Call, II" and her husband, General Theodore Washington Brevard, (CSA) were:
Richard Call Brevard
Note: This "Richard Call" Brevard is the one who died unmarried, sans progeny. According to Findagrave: "Worked in 1880 as a railroad clerk in Madison, FL"
(Strike my earlier statement about "Richard Call" Long's death circumstances. In my haste I confused some of the facts among all the members of this extended family, in particular all the different Richards.)
Caroline Mays Brevard
From Findagrave: "She was an author and historian who published "A History of Florida" to excellent reviews. She also authored a book on southern literature, entitled "The Literature of the South," which was published in 1908 by the Broadway Publishing Company of New York.
"(bio by Martha Reid 19 UDC) Caroline was the granddaughter of FL Territorial Governor Richard Keith Call. She was FL Division UDC Historian from 1900-1904 & 1909-1912. She also served as chairman of the FL Division Education Committee. She was author of "The History and Government of Florida", a textbook used in Florida public schools. She was organizing president of Anna Jackson Chapter UDC, Tallahassee in 1898."
(According to my sources Caroline also never married and died sans progeny.)
Dr. Ephraim M Brevard
(Ephraim's wife and children are correctly represented here.)
Alice Brevard
Alice Hayne (Brevard) married George Humphrey Gwynn. According to Ancestry, "Born in Oaks Plantation Tallahassee, Leon, Florida on Mar 27 1862 to David Walker Gwynn and Caroline Ann "Lina" Blake. George Humphrey Gwynn had 4 children. He passed away on Jun 8 1931 in Leon, Florida, United States." This is his WWI military service record (1st Lt. Marine Corps):
https://www.floridamemory.com/items/show/199945
Alice Hayne Brevard and George Humphrey Gwynn had a son, George, Jr. (m. Mae Steinman). George Jr. was the informant on his father's death certificate. Alice had died shortly after childbirth, and George Sr.'s second wife was Jennie Perkins, with whom he had another child.
https://www.findagrave.com/memorial/138872252/george-humphrey-gwynn
https://www.findagrave.com/memorial/105234758/george-humphrey-gwynn
(Note that Findagrave has not made all the genealogical connections.)
Jane Kirkman Darby
Jane Kirkman (Brevard) and Thomas A. Darby were the parents of "Mary Call, III" (Darby), wife of governor LeRoy Collins. My understanding is that she was their only child.
I found no documentation for the following:
Jennie Brevard
Helen Kirkman Brevard
(Additionally, Findagrave notes three of their children who died young: Ellen, Mary, and Theodore.)