I won't be able to access my own records until probably later today but my interest is piqued.
When you say you are "looking for Margaret Whynti and...", what info is it you are looking for? Since you've not been specific I don't want to spend too much time on it just now in case I'm either duplicating things you already know, or I go off on a tangent.
Will post a couple of items that might help.
Did a very quick search of census records in Banffs and there are a number of census records for Whyntie families born Banffs.
In 1851 there is one family that is a possible, but you may have this already:
Address: Windsor, Parish of Fordyce
James Robb 34, head, crofter ag lab, born Fordyce
Margaret Robb 32, wife, born Deskford
Helen Robb 8,
Margaret Robb 6
Betty Robb 3
John Robb 3 Mo
(all children born Fordyce).
I can't see them for sure in 1861 but there is a possible family living in Kildrummy, Aberdeens. that might be them although there is a slight discrepancy in the age of the boy John and also, the father is not there (she is described as "wife" though, not "widow".
Address: Tyries 2, Parish of Kildrummy
Margaret Robb 42, farmer's wife, born Deskford
Helen Robb 18
Elisabeth Robb 12 (obviously this could be "Betty")
John Robb 9
Alexander Robb 7
Mary Robb 4
George Gray 50, visitor, farmer servant, b.Deskford
(again, all children born Fordyce).
1871, they appear to be in Forres, Morayshire
James is now a spirit dealer and is living with wife "Margret" and children Helen, John, Alex and Margret.
Address, 131 High St, Forres
James Robb 53, spirit dealer, Fordyce
Margret Robb 51, Deskford
Helen Robb 26, dom servant, Fordyce
John Robb 18, blacksmith, Fordyce
Alex Robb 16, mason, Fordyce
Margret Robb 8, scholar, Deskford
1881....
63 & 65 High St, Forres
James Robb 64, Grocer and spirit merchant, Fordyce
Margaret Robb 62, Deskford
Mary Rob(b) 24, general domestic servant, Fordyce
John Duncan 7, grandson, Forres (states mother as Mary Rob)
Haven't looked for Margaret later as you indicate she died 1882.
Don't see James obviously in 1891 but there is 1 James Robb, a 74yo widow from Scotland living with a Berkenshaw family in Newton, Lancaster. Occupation though is shown as a post watchman.
Going back to 1841 now....
Living at Windsor (see 1851)
James Robb 20, farmer
Margt Robb 20
James Robb 4 Mo
Margt Gray 3
(all born Banffs - not specific)
(adults ages usually rounded in 1841)
I would point out again, these are from very quick searches I've carried out and I have done nothing really to verify they are the correct people, they just look likely to me. They are also just the transcripts so are only as reliable as the person that input the info to Ancestry.
Hope these are the correct family and that it helps you out.
Dave