I have studied the lineage of the Dalrymples of Stair and to answer your question about your wife's lineage, the answer is NO!!
There are a lot of family legends as well as genealogy data at LDS that is wrong. No Dalrymple of Stair ever settled in North America.
HOWEVER - if you are a Dalrymple with Cuban ancestry you could be connected to the Stair lineage! - but no sense in going in that direction unless you have a Cuban ancestor.
Who is your wife's grandfather or great grandfather ? I have A lot of info on the different Dalrymple families in Canada and USA. Maybe I can help.
Regards, Don Dalrymple