I believe that the women only accompanied the army as far north as Fort Edward.  Possibly a couple of ranking officers ladies may have made it as far as the Camp at Lake George.

The space in the boats was at a premium to move the landing force down lake. The women would have come down after Ticonderoga was taken.  There never was a proper camp set at the landing and the British only held it for four days.

Also according to Vol XV, Abstract of Entry in Sheriff Court Books of Argyll at Inveraray, as listed in Frederick Richards book:
In his will, " ... Mrs. Jean Campbell, his wife... "  It would seem that they were married March 20, 1732 and she was the daughter of Col. Alexander Campbell of Finab.  She died in Edinburgh on August 20, 1761.

Perhaps Duncan, like so many other ranking British officers had an American "wife", an accepted practice. What?

IMHO
R. Miner