Thank you! It isn't directly the same family (Thomas Robertson Sword was still in Scotland in 1861) but it opens up interesting lines of further inquiry, such as: Were the Parry Sound Swords cousins? Is their brief sojourn in Glengarry area significant considering that is where the baby ended up and also where Thomas's brother Andrew, who stayed in the Rossshire Buffs regiment, found a bride? Or is it just coincidental because Glengarry was a hub of Scottishness.
Your answer was also helpful to remind me where to link Canadian census sources -- rather than Ancestry which is not available without a subscription.
Primarily though, i am trying to find Theresa Adelaide Marsh, whose name was still Marsh until 1870, but who should show up on the 1871 Census somewhere (or the 1870 census if she had gone 'home' to the States) as Mrs Sword, because she lived long enough to have a baby in 1873-4, a baby with definite Sword DNA...or maybe she managed to miss both censuses.
I think it is strange that I've found no evidence of the parents she claims for herself: Alfred Marsh and Janet McKenzie. Or even Alfred and Janet Marsh, since she might have her mother's maiden name wrong...Maybe that is what my question should be: where are Alfred and Janet?