Hi Ostler,
Just spotted this post too...I really should look around more!
The Charlotte Gunn (cousin) in 1861 is as follows in the 1851 and 1841 census returns:
Piece: SCT1851/38 Place: Latheron -Caithness Enumeration District: 19
Civil Parish: Latheron Ecclesiastical Parish, Village or Island: Berriedale
Folio: 0 Page: 9 Schedule: 33
Address: Borgy
SUTHERLAND Donald Head M M 37 Fisherman & Farmer 3 Acres Caithness - Latheron
SUTHERLAND Janet Wife M F 36 - Caithness - Latheron
SUTHERLAND Donald Son - M 9 Scholar Caithness - Latheron
SUTHERLAND John Son - M 7 Scholar Caithness - Latheron
SUTHERLAND Charles Son - M 5 - Caithness - Latheron
SUTHERLAND Margaret Dau - F 3 - Caithness - Latheron
SUTHERLAND Robert Son - M 1 - Caithness - Latheron
GUNN Charlotte Ma-Law U F 60 Pauper (House Servant) Caithness - Latheron
and 1841 census:
Piece: SCT1841/38 Place: Latheron -Caithness Enumeration District: 13
Civil Parish: Latheron Ecclesiastical Parish, Village or Island: Berriedale
Folio: 0 Page: 9
Address: Lower Borgue
GUNN Charlotte F 50 Crofter Caithness
SUTHERLAND Donald M 25 Shoemaker Caithness
ARMSTRONG Janet F 25 Caithness
I looked up her death too, it is:
Charlotte Gunn 84yrs d. 15 Apr 1864 Borguie, Berriedale Fa: Robert Gunn (dec) Mo: Betty Grant (dec) Old Age Inf: Donald Sutherland (son-in-law) present.
There were no more deaths of a Charlotte Gunn until 1899. So I am pretty sure this is her. It means that she never married, but had an illegitimate daughter Janet to a fellow called Armstrong.
I haven't figured out where she fits in yet with John Sutherland and Catherine Gunn (Janet's parents) but I am sure that she will slot into place eventually. I "assume" that her father Robert Gunn is Catherine Gunn's brother or uncle, I have seen stranger relationships on the census returns.
Hope this helps
Jenny