Just found this thread and I'll have to have a look at the extract as I'm intrigued as Kenneth McKenzie, did die 7 Nov 1801 but the odd thing is that his sister Jessie married a James McRobert but that was in 1804.
That James McRobert, a teacher, was born c.1778 and died 24 Jun 1856 in Terregles, his parents were Henry McRobert & Barbara McMillan, his death cert. shows only one wife a Margaret Greive, I can't find her in the 1841 census, so I don't know whether she was before or after Jessie. He had a sister born c. 1790 in Dumfries.
Cheers
Niall