Hi, Perhaps the following ? Is it possible that the following Jennie and Maxine - are your Gladys and Peggie ? Iphey Janie - may be Jennie age 36 ?
Searching 1916 Canada Census - Alberta
Bow River - Sub District 33 - Municipality Roach
finds the following:
Jennie FOSTER age 36 - USA
Jennie FOSTER age 10 USA
Maxine FOSTER age 5 USA
To Canada from USA 1912
Also at the same location:
Louis A. SNYDER age 36 USA
Oscar JOHNKE age 32 Germany
Andrew BORDULA age 17 Russia
Have you searched for / Obtained Registration of Death / Long Form Death Certificate for Wm. Foster - in Montana USA? Searched the 1900 USA Census ?