In the 1970 Swedish Population / Census, there's a woman living at the same address as Jonas Sixten and she's close to his age. Possibly what we would call a common law marriage, but I don't know if Sweden has a similar legal concept. Or she's just renting a room. Or is he renting a room? Or a caretaker? Relative?
Persson, Ester Kristina Katarina
820 41 Färila
Kyrkobokförd i Färila (Ljusdals kn, Gävleborgs län, Hälsingland), distrikt 20, fastighet 49259. Mantalsskriven på samma ort.
Född 24/11 1904 i Järvsö (Gävleborgs län, Hälsingland).
Källa: Mtl Gävleborgs län 1971
Oakland FamilySearch Library