01. Yes, the daughter who died at Sault St. Marie [at least that is what one source says] was Isabel.
02. Sault St. Marie is one of the places where it was possible for the Confederates and Southern Sympathizers where were involved in "The Northwest Conspiracy" to cross into the United States from Canada. The other two common places -- Windsor and Niagara Falls -- were under heavy surveillance.
03. No, Isabel was not married, but she was [according to that same source] betrothed to William Tillay.
04. The E. A. Corbet Loss of Estate, which was the topic of this thread, is closely related to the research I am doing on Robert M. Renick. With a father named Lewis Renick Corbet, at least at the level of family history, the connections ought to be pretty evident. But, the topic of Robert M. Renick, Copperhead Extraordinaire, probably doesn't belong in this thread and may not be of general interest. Please send me direct email [I think the way this forum operates that address will be visible to you.], I would be most happy to share what I have learned, and would appreciate checking some facts concerning Robert's brothers. [I am imagining that you are in the line of one of the boys who went to 'the left half of the state', rather than one of the boys who returned to Greenbrier.]