The family you seek is a near branch of my family.
John Armle (a Confederate Soldier) was a son of Joseph Duncan ABNEY by Joseph's first wife, Sarah SEARCY.
Rebecca (John's wife of the 1870/1880 censuses you mentioned) was Rebecca SMITH.
"Ellen", the sister was actually Nancy "Ellen" ABNEY (b.05 Feb 1863 in Hopkins, TX & d.24 Oct 1895 in Granger, TX. She was John's 1/2 sister by Joseph's third wife, Keziah.
John Armle ABNEY descends from Dannett ABNEY Sr. as follows:
1. Dannett ABNEY Sr. m. Mary (LEE?) 2. Dr. Abraham ABNEY m. Cassandra (MEREDITH?) 3. Dr. Nathaniel ABNEY m. Lucy COLLINS 4. Paul Collins ABNEY m. Dorothy "Dolly" RUTHERFORD 5. Joseph Duncan ABNEY m1. Sarah SEARCY (above)
I descend from Joseph's youngest brother, Robert Rutherford ABNEY (who m. Mary Ann ROBERTS).