I know this is an old post, but I figured I'd post a response just to "answer the questions" anyway.
The Alexander she married was Henry W. Biography: Vincennes in picture and story. History of the old town, appearance of the new. Full colonial history, including George Rogers Clark's own account of the capture of the village (1902)
H. W. Alexander. Henry W. Alexander was born in Greenville, Ill., Sept. 7, 1852. His ancestry on his father's side was of the Sewell family of Maine, and on his mother's side of the Wilkins family of South Carolina. He at- tended the public schools of Greenville, and was graduated from the Greenville High School: In 1872 he entered the University of Michigan, at Ann Arbor, where he took the classical course and was graduated in 1876, taking the degree of A. B. He immediately entered upon the study of law under the pre- ceptorship of Judge Phelps, at Greenville, Ill., and was admitted to the bar on examination before the Appellate Court of Illinois at Mt. Vernon, in 1879. In 1887 he located in Vincennes, where he has since remained in the practice of his profession, with which he has combined a general real estate and loan business. The latter has grown to such dimensions as to pretty well absorb his attention and in this line Mr. Alexander has made a reputation as a prompt, reliable and successful dealer. In politics he has always been a Republican. He is a member and was for many years clerk of St. Jaroes' Episcopal Church, of Vincennes. Mr. Alexander was married, Oct. 22, 1884, to Miss Flora D. Portmess, of Terrell, Texas. They have two daughters.
Johnnie, the brother, died at age 11.He and his mother are both buried in Elmwood Cemetery, Flora, Clay Co., IL - per memorials on Find A Grave.