If we have the right link, then perhaps your mother in law would know who the parents were of Mary McIsaac who married Donald "Big Dan" McIsaac-Mary was first cousin to Donald who married Sarah
and Big Dan(Donald) MacDonald was brother to Sarah aka Sarah.

Donald McIsaac had a sister Catherine who married Sarah's brother Alexander. Sarah also had brothers Daniel (Mary Madore) and John(Henriette Ryan) and sisters Ann(Thomas Medore) and Mary(Frank Madore)

James MacDonald and Mary McIsaac believed to be the names of Sarah's parents. His ancestors or maybe even him, came from the Isle of Skye. His children were born in Inverness County.

Don't know who Mary, Donald or Catherine McIsaac's parents were. As they were first cousins, I assume that Mary's father was brother to Daniel and Catherine's father. If your mother in law could tell me anything about Sarah's parents or even Donald's it would be a Godsend.

Rhon