I am descended from the youngest son of John N. McCombs and his second wife, Laura. The information I have about Mary Jane McCombs's husband, John B. Brown, is that he died October 12, 1876. The birthdate I have for Lillie Clare Brown is May 5, 1871. Lillie had an older brother, Will McCombs Brown, born July 3, 1867. The source of information is a genealogy done in the 1890s. Since there is no mention of the death of Mary Jane, I would assume that she was still alive at that time. My mother still talks of visiting the relatives of the Brown branch.
Incidently, the farm house built by John McCombs in 1858 to replace the log cabin is still standing and quite beautiful. It was owned by McCombs descendants until about 1980.