My goodness, we do have some coincidences here.I know practically nothing about Uncle Art Grobe, just that both he and Laura were living in Seattle by 1920 and I last visited them in their home there in 1971.
Laura McLeod was "of" Cape Breton, Nova Scotia, though she wasn't born there.Her father, a miner, was born there as was her youngest sister.Laura was born in Butte, Montana, in the 1890s.By 1913 when her oldest sister married, they were living in Prince Rupert, B.C., where her father had a store having ruined his lungs mining.I believe he worked at one time at Nelson (is there mining there?).
Not long before Laura and Art married, she lost a leg in a street car accident in Seattle.(We disrespectfully called her our aunt with the wooden leg and the cedar chest, but only when she wasn't listening!)They had one daughter, born probably late '20s.
Laura's mother was a MacDougald (Baptist) from Eastern Ontario.
I've not heard of your Sara Jane before.She and her David Edward Grobe would seem to be (almost) a generation older than Laura and Art.The name Grobe being as uncommon as it is, there may well be some connection.I hope you'll let me know if you find it!