after more investigation I believe that my mother's birth parents changed their names vs my mother being adopted out.
Somewhere between their arrival in the early 1900's and March 1916 they choose to use these more anglo sounding names on birth certificates, at least for my Mom. My mother's sister Teckla a.k.a. Tillie also adopted the "Jamieson" last name. The son Frank did not. He retained the birth name of Juzwiszyn and settled in the Okanagon.
Mitchell / Mike died at Gilbert Plains in 1935. If anyone has any info it would be greatly appreciated.