Sarah Matilda died sometime after the 1880 census. Have not located a death record for her Her husband, William Barnes remarried to a lady named Clara and my mother says that she remembers my grandmother visiting with "Aunt Clara". It is confusing since this Clara was not related by blood, but rather she was the 2nd wife of her uncle by marriage.
I will try to locate William in the census records. It is interesting, like George William's name was not Powers in the first census he appears in (1860, Wythe County, I believe). His name was Cook. Once they came to WV, he also took the Powers name.