>Amusingly, in real life my grandmother didn't actually know she
>was Canadian until she applied for a border crossing card a few years
>ago. She always assumed she was born in Fort Fairfield, Maine, like
>Gramp was. Even U.S. Social Security never noticed; it took the State
>Department digging around to discover that she was actually born just
>over the border in Grand Falls, New Brunswick. (In 1928! Canada
>wasn't a fully independent state until 1931. I think that technically
>makes her a British subject, although the point is moot since the U.S.
>government basically said, "Ah, the hell with it, nobody knew any
>better in '28 - have a passport." :)

I felt like checking so:

She was a Canadian citizen, which in 1928 was a special class of British subject<1>, (created by the 1910 Immigration Act). However she probably lost that citizenship long ago due to the ten year limit on living abroad imposed by the 1947 Immigration Act.

Depending on her parentage she may have US citizenship on a jus sanguinis basis.

<1> This is a sense of British subject that is no longer in use. These days "British subject" only refers to subjects of the Crown who are not citizens of any Commonwealth nation.