There is a Martha ROPER (b abt 1808 - NC), widow of Jacob ROPER, found living in Georgia with her children in 1860, who might somewhat fit this description, however she was already married to Jacob in 1850 residing in Keiths, Lumpkin County, GA.
Possibly a better candidate is the M. ROPER, age 45 (b abt 1815 - GA) shown to be enumerated in the 1860 Census at Talladega County (Northern Division), Alabama, at Census Page 166.
Dr. L. David ROPER is already showing James F. ROPER to have married a Martha BARTLEY on 09 Jan 1851.This James F. ROPER is shown to be the son of John ROPER and Sarah FINCHER.See Dave's ROPER Family History website for details:http://www.roperld.comhttp://www.roperld.com.
This James ROPER's first wife is shown to be Elizabeth (b abt 1802 - NC).The eldest son is Hiram W. ROPER (b abt 1827 - GA).
In 1850, this family is shown to have been enumerated in Chambers County, AL.By 1860, the children of James and Elizabeth seem to be scattered, so the proposition that James had by then died leaving Martha as a widow seems very plausible.
In 1870, it appears that this same individual is actually shown as Martha ROPER, age 59, born in GA, residing in Clay County, AL.A Martha VINCENT, age 11, and Susan VINCENT, age 9, are residing with her.A Vincent household, with a child "M. VINCENT", age 2, was shown to be adjacent to "M. ROPER" in 1860.
It is less readily apparent whether this Martha is still living in 1880 and, if so, where.