Dollylee contacted me with a possible 1916 census entry but she didn't have time to post it here so I'll do it for her:
1916 census for Manitoba, Saskatchewan and Alberta - Selkirk District, Manitoba
George Sebeiston, head, 55, born Manitoba, fisherman
Anne S Sebeiston, wife, age not given, born Manitoba
Mary Sebeiston, daughter, 13, born Manitoba
Donald Sebeiston, son, 7 born Manitoba
Mima Sebeiston, daughter, 5 born Manitoba
David Sebeiston, son, 3, born Manitoba
William Sebeiston, son, 3 months, born Manitoba
The age for William fits and it's possible that Mima could be a nickname for Catherine although that might be a stretch. That's the best we've found so far.
The words "Treaty Indian" are written over top of Anne's birth place and religious affiliation and in the "other languages spoken" column it says "Indian" for the entire family. I'm not sure whether the reference for "Treaty Indian" applies just to Anne or the entire family. Given the fact that at that time a native woman would lose her treaty status if she married a non-status native man, it seems likely the reference was to the entire family.
Jacquie