Hi Lisa,
I don't have a marriage for Isabella, and am thinking that she may not have married. The last I know of her was after her mother died in 1919, she signed a waiver to allow for her brother-in-law John Welsh Hamilton (Catherine Edith's husband) to apply for the Administration of her mother's Estate. At the time she signed she was a spinster. and age 35 and living in Saskatoon.
If she did not marry, she likely went to live with one of her brothers, so it's on my todo list to see if I can find a burial for her. But it's a long todo list and it'll be some time before I make that attempt. Actually, I'm hoping someone may post on Billion Graves or Find a Grave. It is also possible that at the death of one of her siblings that an obituary may have indicated the surviving brothers or sisters, providing names or place of residence. Also, if there are directories for Saskatoon for 1918, 1919 and up (likely at Sasktoon library) then we may be able to find, where Harriet lived before she died and who she lived with and where Isabella lived before and after her mother's death if she stayed in Saskatoon.
On another topic, have you had your DNA done? My results are on FamilyTreeDNA so if you ever think about it (or get as a gift as I did), please consider doing so. It's a fascinating way to validate relationships and break down brick walls but there's quite a learning curve. We'd definitely match if you proceed with the test, and I'm hoping for some McBride matches that match both of us and will help us get back to the McBride's back in Tyrone Ireland. Ancestry doesn't allow DNA testing in Canada yet, but FamilyTreeDNA does and they have the largest genealogy testing database. Here is the link if you want more info....
www.familytreedna.com. Please let me know either way.
Regards,
June