Yes, my grandmother (Mabel) was the daughter of Collin Johnston. Guessing the note my mom made may be referring to Collin's brothers and sisters.

I have just started to try and track my family’s ancestry and wonder if anyone can give me some ideas on tracking down information on my great grandfather’s family. His name was Colin Johnston, born June 1866? in Winnipeg and came to Edmonton then to Athabasca Landing. He married Marguerite ...