Hello Barbara: I hope this will help.I find Mahala and children in the 1880 Patrick Co Va census without husband, Joseph. Whomever transcribed this census at Va gen Web has the daughter you mention as "Susanna J."(see below). Now in my Patrick Co Va families, I have a Joseph F. Wimbish who married Sarah E. Shelton in 1874 AND a Serina Jane Wimbish who married Thomas N. Shelton in about 1865.
The Wimbish families that I have were from in NC. but may well be related to the ones in VA. I feel that the Joseph Britt Wimbush you are researching must be related to the William Wimbish family I have; that is: Wm Wimbish married Rebecca Ellen Reynolds in 1846. I have from the census these children for them: Jospeh F, James Lee, Elijah T, Mary E and John L. I'm sure there could be more.
1880 PCVA census 1880 Patrick Co Va census 288Mahala J. WimbishWF46FarmerVirginia Susana J.WF18DaughterDoes HouseworkVirginia Julia V.WF16DaughterDoes HouseworkVirginia PeterWM14SonLaborer on FarmVirginia Flora A.WF12DaughterAt HomeVirginia Sarah M.WF9Daughter
Samuel G. CritzWM21Son-in-lawLaborer on FarmVirginia Mary E.WF20DaughterDoes Housework