Emily - don't know if this confuses things further (!), but there is an entry in the Monumental Inscriptions for Sutherland, Balnakeil (which is the Durness burial ground) which may be of interest.
Stone 99.
"Angus Sutherland ground officer Durness 7.11.1827 45, w Bar N' Rob Sutherland 20.4.1872 91 , gs Ken F Sutherland 7.12.1862 10, ggs And McKay 3. 1900 7 months , ed s Robt"
My interpretation of this is
Alexander Sutherland, Ground Officer, Durness, died 07/11/1827, age 45 yrs. His wife Barbara, daughter of Robert, Sutherland died 20/04/1872, age 91 yrs. His grandson Kenneth F Sutherland died 07/12/1862 aged 10 yrs. His great grandson Andrew McKay died March 1900 age 7 months. Stone erected by (Alexander's) son, Robert.
(Please anyone with more knowledge than I, feel free to correct any errors!)
Hope this is of some help.
If they turn out to be your family, I have photos of the burial ground, which is right on the coast, a lovely, windswept place with a stunning view out over the sea. My husband has ancestors buried there, who are also Sutherlands - although I don't see a connection at this stage.
Kind Regards
Ellen.
Added later: Sorry Emily, just noticed that you have already had this info on another thread and discounted them.