Left 8 siblings behind so its hard to say if they stayed or left you would have to chase down each of them.
They are all on Scotland's People
https://www.scotlandspeople.gov.uk/ if you don't have an account you can open one and you want to search people select church registers fill in surname only select count and parish Cromarty then his search and sort by parents you will them all under their parents. These are baptism not births. If you want to see a record it will cost you 6 credits (price of 2 med Tim's and a fritter) if not you have their births.
Margaret got into a problem after Donald died but with so many children its understandable.
National Records of Scotland
Reference SC24/10/475
Title Robert Morrison, miller, Shoremill, Cromarty vs Widow Christain Urquhart or Bain, Rosefarm, Cromarty: Debt
Dates 1855
By the looks of it a number of people ran into the same problem at Rosefarm.
http://catalogue.nrscotland.gov.uk/nrsonlinecatalogue/welcome.aspx select the search button and type in Rosefarm.
Perhaps they left Scotland for a piece of land they could call their own its hard to say why, but land ownership is expensive in Scotland which is why most went to Canada. Then again maybe they liked snow and the thought of an occasional hurricane or the prospect of been chased by a moose or bear.
Don
I should add there are a lot of Bain's in NS BMD you should see if some of his siblings found their way as well.
