She is either a daughter of Fraser of Foyers, by his wife Janet, dau. of John MacPherson, 3rd son of Ewen Macpherson of Cluny (J.Stewart, The Camerons)
or:
Mary, dau. of John Cameron in Acharn, Morvern "a younger son of Lochiel - uncle to Lochiel of the '45" (Sir Colin McKenzie)