I don't know. I suspect it would have to do with proving you shared the same household and were responsible for that person's support. I do know that my mother in law stayed in Ireland with her oldest son until my father in law could afford to bring them over here (two years). Maybe that's how it'll have to go. I'm not very familiar with immigration law at all. I do know that people who emigrate need to have a sponor here in the United States who is supposedly liable should the person end up insolvent or on assistance. I know, because I was asked to sponsor someone about four years ago. Upon reading the document, it looked like my personal assets would be on the line even if the person got sued and as I didn't even know the person coming over, I refused. I don't know if the document is a formality, but it shouldn't be. And as long that sort of responsibility is required to vouch for someone, then I don't see the problem.
RE: I don’t know. I suspect it would have to do with proving you shared the same household and were responsible for that person’s support.
The only way we can prove this today is by a marriage license from the previous country of domicile.
Otherwise, anyone can just state that he or she shares the same household and have a recognized authority from that country draw it up and notarized.
But then I don’t see how that differs much from a marriage license. You still need some PROOF.
Whether you want to call it marriage or not, you still need to use a similar procedure.