Private User, you didn't drop links to the profiles of James and Isabella, so I've dropped them here:
Also, I'm not the Geni project police, but because I don't see any mention or implication of Ayshire here, it seems to me that this discussion shouldn't have been attached to the People Connected to Ayrshire project.
I decided to do a quick search of the Internet for James and Isabella, and discovered that this is a mystery that has confounded others:
• https://forum.familyhistory.uk.com/threads/james-ross-and-isabella-...
• https://www.rootschat.com/forum/index.php?topic=801898.0
Here are their WikiTree records:
• James: https://www.wikitree.com/wiki/Ross-19248
• Isabella: https://www.wikitree.com/wiki/Lamont-1401