Martha E. Carpenter Gibson

This is a photo of my gg-grandmother Martha E. Carpenter Gibson, seated to the left of her grandaughter Delomia Gibson Watts Fincher. Martha Carpenter Gibson was born in Troy, Pike County, Alabama on 26 August 1837 and died in Naples Texas on 24 January 1922. She married John J. Gibson in Pike County Alabama on 1 February 1860. John served as a Private in the Civil War in Company K of the 37 Alabama Infantry. Martha and John never had children, but reared my g-grandfather, Robert James Gibson. I can find no record of an adoption, but Robert James Gibson did carry their last name. My deceased Aunt suspected that his natural parent's last name was Tubbs, but I have not been able to confirm that information. The 1870 Federal Census records reflect that John and Martha were living alone as of 8 July 1870. Robert James Gibson's date of birth was 14 July 1870. John, Martha, and Robert moved to Texas between 1870 and 1880. I'd be pleased to hear from anyone who has knowledge of this Gibson and/or Carpenter or Tubbs families.