I believe I can help you with Margaret Catherine Sexton Powell. She was my great-grandfather's first cousin. Margaret was the daughter of Andrew H. and Mary Malcom Sexton. Margaret was born on 5 July 1840 in Cabell County, WV/VA. I have the wedding date to Franklin Powell as 29 July 1868 in Hamilton County. Margaret's mother died in 1846 in Cabell County. Her father's second wife was also named Mary (Reynolds). Andrew and his second wife are buried in Farnsworth Mt. Zion Cemetery in Wayne County, Illinois.
I do not know Margaret's death date. Have you check the Illinois Archives Death Index for her death date? Margaret had many relatives that lived in the Wayne, Jefferson, Franklin, and Jefferson Counties of Illinois.
Let me know via e-mail if you want more detailed information.
K