I too am looking for this person. There is a Martha Benge Duncan McDonald listed on Find-a-grave whose husband is listed as David Lewis McDonald. There are hints that she may have been the daughter of Dorcas Lightfoot Benge Duncan, but I can find no supporting evidence of this fact.
My great, great grandmother’s name was Duncan!
Her husband was an Irish man
I too am looking for this person. There is a Martha Benge Duncan McDonald listed on Find-a-grave whose husband is listed as David Lewis McDonald. There are hints that she may have been the daughter of Dorcas Lightfoot Benge Duncan, but I can find no supporting evidence of this fact.