I may have the answers to some of your questions.Your Martha was dtr to Rebecca Florence Hanna and Lee S. Bush. I have not found documentation of their marriage but they were together in the 1860 Fulton Co AR census. He died in 1862 during the CW. She remarried Geo W Barnes, also not found marriage for them. Martha married Jesse Jackson ca 1882 in the Izard Co area, could have been Sharp or Fulton Co. No marriage record for them either.
I did not know her middle name was Elizabeth so only have her as Martha R or Mattie R. I found a death for a Mattie Jackson in Craighead Co May 18 1928 who I believe could be her. She is listed in the AR death index so there should be a death certificate to verify if that is truly her.
I am related to the Hanna side of the family.Rebecca Florence, mother to Martha, was older half sister to my great grandfather, John Hanna b 1871 Izard Co. His father was David. David was married before to Rachel Dempsey and can be found in the 1850 Hardin Co TN census. Then he moved to AR and can be found without Rachel in the 1860 Fulton Co census, then in 1870 with his new wife Thursey and some of the children in 1880 as David CANNEY. Hanna was was often pronounced Hanney and is sometimes enumerated that way.
Would be interested in hearing from you. There is a lady that is directly descended from Rebecca by her marriage to Geo Barnes and their dtr, Florence Elizabeth Barnes who married Jefferson Davis Mathis in Izard Co. She is also researching this family.