From the Warren Co. VA Minute Index we know that Ann M. Johnston picked Morgan Johnston as guardian in 1850.
I strongly suspect she was the daughter of John I. & Emily (Brownley) Johnston, so she went to live with her Uncle & Aunt, being related to both.
1850 Warren Co. VA Morgan Johnston 50, Nancy 50, Ann M. 6. I do not know if other have her listed at their child or not. Said Nancy/Ann would also be related to her mother's family--Brownley.
Marriage Record in Warren Co. VA: Buckner G. Ashby 26 years, single, born & living in Clarke Co. VA, Farmer, parents Buckner & Sophia G. Ashby married on 13 Mar 1862 to Ann Morgan Johnston, 17 years of age, single born & living in Warren Co. VA, parents Morgan & Nancy Johnston, married by Rev. Robert RR.S. Hough (Methodist Minister)"
Warren Co. VA Birth Registry has two of their children listed:
female ashby born dead Feb 1866, also listed Death Registry.
Alice Maud Ashby born 15 Aug 1869
Found on 1870 Warren Co. VA census: B.G. Ashby 35, Ann M. 26, SOPHIA B. 7, Wm. B. 6, Annie 3, Alice M. 10 months
According to her tomb stone she was born on 18 Feb 1844 and died 20 Mar 1880, buried in Prospect Hill Cemetery, Front Royal, VA, next to Morgan Johnston & his wife Ann Brownley
1880 Warren Co. VA: B.G. Ashby 45, SOPHIA B. 16, Willie 8, Nettie B. 12, Alice Maud 10.
I have not tried to trace the remaining people on census.
The notes of Hunter B. McKay have not given me direct answers to the ancestry of many of the female lines of his mother's line who was Etta Double Sowers, her father was George H. Sowers and her mother Martha Virginia Sowers. Which is why her middle name was "Double".
Her mother Martha V. Sowers was the daughter John W. Sowers & Mary Emily Mitchell.
It is the families of Mary E. Mitchell I have been trying to find out more. Mary E. Mitchell was the daughter of Wm. Mitchell & Matilda Johnston.
The question I have been picking at-- who were the siblings of said Matilda Johnston-- were they John I. & Morgan Johnstons ?
I found a note in my the Ashby File from Hunter B. McKay's note written by his mother Etta D. (Sowers) McKay
"The Ashbys that I know are not related to the McKays, but to my mother (Mrs. George H. Sowers) through the Mitchels and the Johnstons. Buck Ashby who lived at Ashby Station (now Bayard) married Miss Johnston who was Sophia Ashby's mother--you have heard me speak so often of Sophia"
I think I am on the right tract finding the ancestry of Matilda Johnston, but still need more information from Clarke & Warren Co. records.