Ah, ok. Then it makes no difference any longer, spouse or fiancee, neither can get a visa.
But if they entered the US illegally and are married to a LPR rather than citizen, it's going to be many years before they can get a visa anyway. So I wouldn't worry about the country ban for now, I'd focus on getting them out of the US asap so any overstay ban doesn't get longer, and getting the I-130 filed asap when eligible to secure their place in line. Then hopefully by the time they are at the head of the line to get the visa, the country ban will be lifted or amended anyway.