They were ethnic Germans from the old Austro-Hungarian empire. Today, their place of birth could be in any one of a half dozen countries. My father was also an ethnic German born in Hungary.
Name: Peter Keefner Death Year: 1949 Burial City: Glenbain, Saskatchewan, Canada
The 1911 census has Lizzie born in the US, coming to Canada in 1905 with Peter & Julia. Ditto for the newly released 1921 Canadian Census.
I found a Peter Kuefner (or "u" with an umlaut over it) arriving in Philadelphia in 1903, aged 26, a blacksmith by trade, last of Moramorsk (?), bound for his uncle, Friedrich Sattelmayer, Roanoke, Illinois. This is near Peoria.
This might give you some idea of where Lizzie was born. I would be interested in seeing when Julia arrived. Maybe getting Peter's naturalization records would provide some information.