mcajd01,
Don't know if you have checked out the IGI or any of the census information, but I've come up with this so far:
From 1881 census:
8 Burnside St, Campbeltown, Argyll
Volume 507 ED 15 Page 3
John DONALDSON Head M 27 M b Glasgow, Lanark Cooper
Margaret DONALDSON Wife M 24 F b Campbeltown, Argyll Cooper's wife
Janet DONALDSON Daughter 2 F b Campbeltown, Argyll,
James MC ALISTER Bro in law Boarder M 29 M b Campbeltown, Argyll, Fisherman
Agnes MC ALISTER Bro in Law wife M 21 F b Campbeltown, Argyll, Fishermans Wife
Harveys Lane Campbeltown, Argyll
Volume 507 ED 20 Page 2
Archd. MC ALLISTER Head M 57 M b Argyll, Scotland Fisherman
Janet MC ALLISTER wife M 55 F b Argyll, Scotland
Alex. MC ALLISTER son U 22 M b Campbeltown, Argyll Fisherman
Robt. MC ARTHUR U nephew 21 M b Argyll, Butcher
Duncan CAMERON boarder U 12 M b Argyll, Scholar
Archibald & Janet married 4 Jun 1850 Campbeltown (see Familysearch for exact baptism dates) – six children :
James 1851, Mary Muir 1853, Margaret 1856, Alexander 1859, John Thom 1861 and Janet 1864.
A few leads to follow up there.
Good luck
Nell