In the 1881 census, Hugh Craib and family are enumerated in Sunyknow, Mortlach. Here's the extract from the LDS transcription of the 1881 census.
Dwelling: Sunyknow
Census Place: Mortlach, Banff, Scotland GROS Ref Volume 162 EnumDist 7 Page 6
Marr Age Sex Birthplace
Hugh CRAIB M 46 M Keith, Banff, Scotland
Rel: Head
Occ: Crofter
Jane CRAIB M 39 F Mortlach, Banff, Scotland
Rel: Wife
Hugh CRAIB 1 M Mortlach, Banff, Scotland
Rel: Son
Isabella CRAIB 1 F Mortlach, Banff, Scotland
Rel: Daur
Aney GRANT (CRAIB) U 16 F Mortlach, Banff, Scotland
Rel: Step Daur
Occ: Gen Domestic Serv
Margaret GRANT (CRAIB) 12 F Mortlach, Banff, Scotland
Rel: Step Daur
Occ: Scholar
John GRANT (CRAIB) 10 M Mortlach, Banff, Scotland
Rel: Stepson
Occ: Scholar
James GRANT (CRAIB) 8 M Mortlach, Banff, Scotland
Rel: Stepson
Occ: Scholar
Sunnyknowe was one of the crofts in the area marked as Backhill of Kininvie. See
https://maps.nls.uk/geo/explore/#zoom=16.0&lat=57.48496&lon=-3.09861&layers=257&b=ESRIWorld&o=100&marker=57.48554,-3.14418 (zoom in if necessary).
No trace of it now remains. If it had still been there it would have been in this view
https://www.geograph.org.uk/photo/422207 - somewhere in the middle distance, left of centre.