I am now proposing as a THEORY (needing more evidence), that Mary (Mrs. William Ewing) might have been the daughter of Thomas and Mary Logan of Laurens County, South Carolina.
Records from Duncan's Creek Presbyterian Church in Laurens County, South Carolina (18th century) show that a Thomas Logan had settled in that area and became a church "elder", having been "ordained" while still living in Northern Ireland, whence he emigrated.
Researcher/descendant Heather Logan has stated that Thomas and his wife Mary arrived in North America (probably the port of Charleston, SC) about 1768, when Thomas was about age 36, Mary about 29, and with two young sons, William and John, both under 10.
Researchers have also determined that, after arriving in South Carolina, Thomas and Mary had a daughter, Jane, born about 1769, who married William Craig in Laurens County.
I am now proposing as a THEORY (needing more evidence), that Thomas and Mary Logan might have had another daughter after Jane, born about 1773 in South Carolina, and named her Mary. About 1793, this Mary married William Ewing, son of Thomas and Sarah Ewing. The Ewings were also members of Duncans Creek Presbyterian. William and Mary Ewing were among the group of families from Laurens County who migrated to the Northwest Territory (what became Southwestern Ohio) after 1800 and soon took up government land in what was to become Franklin County (and Union County), Indiana. William and John Logan, sons of Thomas Logan, were also among the Carolina-to-Indiana migrants.
The evidence supporting this THEORY is circumstantial, based on timing, geographic proximity, likelihood of social interaction, shared religion, and similar migration. I do NOT have a marriage record showing the maiden name of Mary, William Ewing's wife. Nor do I know of any Will possibly left by Thomas Logan, which might mention his children. Naming patterns lend some slight weight: William and Mary Ewing named their first two daughters Sarah and Mary. Sarah was almost surely named for her paternal grandmother, that is, William Ewing's mother, Sarah (possibly Vernon) Ewing. Second daughter Mary might have been named for her maternal grandmother, Mary (maiden name unknown) Logan. (Of course it is also possible that this daughter Mary was just named for her mother, Mary Ewing.)
Does anyone have any information that would either support or refute the THEORY proposed? Please contact me directly at firstname.lastname@example.org.