Well now!
I was wondering why Bella might have been in New Jersey and contemplating the fact that Samuel's last appearance in the Montreal Directory was 1903-04 where he is described as a second hand dealer. And no apparent burials for Samuel or Mary in Quebec.
Well....
I believe I might have located Samuel and Mary in Jersey City New Jersey in the 1905 census.
Samuel born England Sep 1929 (matches 1901 census) Retired Parents born England
Mary born Apr 1933 (matches 1901 census) born Scotland (more correct, I believe) Parents born Scotland
Immigration timing seems to be an issue though, as the couple apparently indicate they have been in the US 20 and 40 years respectively.
I can't post a link from the website I found this record on but would expect you could find it on the familysearch website as they seem to have US censuses (didn't look myself, though).
Bella....
Baptism in the Drouin Collection: posted earlier by Jool (reply #10)
Isabella Nichol Edwards
Born 30 Nov 1863 (so date of birth matches the census but not the year)
Baptized 28 Apr 1864
Parents Samuel and Mary Edwards
Both parents signed as witnesses
Census entry could possibly be an error of some sort.
Mary....
With her birthdate you might be able to find her birth in Scotland
https://www.scotlandspeople.gov.ukThis is a pay site but the indexes are free to use. You would have to pay for the record info.
So, much food for thought.
PB