Thanks Kate. I have some additional comments to add to yours:
The Frederikia Gauley you referred to on the 1881 census I believe is actually Prudentia Gauley. Either the enumerator or the transcriber made a mistake on that census. Prudentia was married to James A. Gauley (same last name, but don't know the relationship). He died in 1878. The Elizabeth Gauley and Martha Cousins who were living with Prudentia in 1881 were Prudentia's first cousin Elizabeth Gauley Cousins and Elizabeth's mother-in-law Martha Jane Matthews Cousins.
The Angus and Sarah Murray you referred to I think are actually James Murray and his wife Sarah Ogilvie. Not sure where the name Angus came from, perhaps it was a middle name or there was a transcription error.
The Stanstead connection is interesting. I must have been way off base in tracking them to Michigan.
Feel free to email me directly. If this is your line I may have some information of use to you.