Hi sbw, I have been thinking about this very lovely photo...the back of it makes me think late 1870s design, although I just don't know if a photographer in Quebec would follow the same fashions for card backs as an English studio. I'd guess that he would, because you have to buy what's available, and if what's available is roses & cherubs, for example, that's what you end up with. It's just a guess, though.
J.E.Livernois was a drugstore as well as a "photographr" (did you notice the misspelling?) and was embroiled in a dispute with the provincial government over what he could sell to the public, back in the 1970s, maybe 80s. As a photographer, the company took LOTS and LOTS of photos, some of them very important portraits of Quebec historical figures. An annoying number of them are posted on the internet in %&#@& .pdf format...grrr
But as many as there are, there is not one back to compare with, that I have found.
It's very difficult to date children's photos by the clothing, as children's clothes didn't follow much fashion, and very young boys and girls were dressed alike...Your best bet in this regards would be old rowley...if he doesn't drop in you could pm him.
So back to my best guess of late 1870s going by the design on the back.
Cheers,
China