Margaret possibly had at least one brother. I did a search scotland wide from 1855 to 1805
MARGARET GUTHRIE Chr: 11 SEP 1782 Arbuthnott, Kincardine, Scotland
ALEXANDER GUTHRIE Ch: FEB 1784 Arbuthnott, Kincardine, Scotland
Regards, Steve
You'll have found Margaret on the IGI. What to do then is click on the batch number on the bottom left of the page. On the next page enter on the top right boxes the fathers name only.
And in this case you come up with Alexander.
It's an 'extracted' entry and only give the fathers name as Robert Guthrie
Logged
McDonald originating in Aberlour. Smith (Aberdeenshire/Aberdeen), Esslemont, Christie, Robbie; Scott (in Aberdour). Crosbie and Willison. Borders: Lawrie, Thomson, Paxton, Peacock, Amos, Robson, Turner, Bertram, Watson