I think that Margaret Danielston of Danielston & William Cunynghame of Kilmaurs, Earl of Carrick are not the correct parents of George Cunningham/Cunyinghame of Belton.
I think that William Cunynghame of Kilmaurs and William Cunynghame/Cunningham of Belton have been miss-merged.
From references on William Cunynghame of Kilmaurs (b. c.1330 d. c.1396) his son eldest son predeceased him so the 2nd son was & heir and succeeded him, Sir William Cuninghame of Kilmaurs (d. 1418) and his son & heir was Sir Robert Cuninghame of Kilmaurs. George Cunningham/Cunyinghame (b. c.1410 d. 1482) was born after the death's of the two parents Margaret of Danielston & http://www.geni.com/people/William-Cunynghame-of-Kilmaurs. And George would not be son of Sir William Cuninghame, of Kilmaurs because he died at a earlier date then George's referenced father.
From references about George Cunningham/Cunyinghame of Belton, Retour of Inquest held in the burgh of Dumfries, 5 Feb. 1471, finding George de Cunynghame heir to his father Sir Wm. Cunynghame knt, who died about 6 weeks before. And I believe that Anna Montgomery may not be the correct wife or George had a second wife named Elizabeth because of a Charter by George Cunnynghame, to his son in law John Hay & dau. Elizabeth Cunnynghame, reserving the liferent to the said George and a reasonable terce to his wife Elizabeth.
So there are at least two points where the references do not agree on the parents Margaret Danielston of Danielston & William Cunynghame of Kilmaurs, Earl of Carrick that are connected.
1. The years of birth & death of William of Kilmaurs (& Margaret) & George
2. That George was heir to his father William of Belton, where William of Kilmaurs' heir was another William of Kilmaurs.
If there is no objection, then I will be removing Margaret Danielston of Danielston & William Cunynghame of Kilmaurs, Earl of Carrick as parents of George Cunningham, Sir Laird of Belton.
If there is any objection then please state where a reliable reference is for keeping this relationship.