Born Isabel (or Isabella) Gunn. Disguised as a man she signed a contract as a labourer with the Hudson's Bay Company with the Red River settlement of Manitoba, in 1806, and was sent as part of a brigade to Pembina in the fall of 1807. On December 29, 1807, Fubbisher "felt poorly" and sought to rest at the Alexander Henry's house.

Henry's journal records Fubbister was "uttering most dreadful lamentations... begged my assistance... requested I would take pity on a poor helpless abandoned wretch, who was not of the sex I had every reason to suppose. But it was an unfortunate Orkney girl pregnant and actually in childbirth." Thus discovered, Isabel Gunn and her son were soon shipped back to Scotland against her will, where she ended her life as a vagrant.