From correspondence with Bill Currie:
My dad told me that Grandma Currie and Norma were visiting her parents in Port Arthur when she died. He (Jack) said he remembered his father gathering him and the rest of the kids together to tell them Norma had died. I believe Norma is buried with Grandma Currie's parents as "Baby Snook" (it says in the cemetery registry - attached) - photo of the Snook burial site attached. I wonder if they wouldn't have allowed her burial there if they knew she had diphtheria.
and later that same day:
Michael: I had another look at my notes on the Thunder Bay cemetery document and my comments re "Baby Snook" don't really work as Norma was still alive when Baby Snook was buried. So Baby Snook is a mystery. I think Grandma Currie had a brother; don't know about his marriage status but could have been his. Also Grandma Currie's parents were buried before Norma died so, if Dad's story has any basis in fact, it must have been somebody else she was visiting (her brother?). I have found genealogy to be full of these little mysteries even with relatively recent and well documented people. There is a lot of speculation involved once you go further back where good records are hard to come by and imprecise when you find them.