Well, there is no way to guarantee that it will not become a problem either now or in the future. All it takes is an upset family member, neighbor, friend, ex, etc. to report her and provide evidence (if it exists) and she could even lose U.S. Citizenship
in the future because her status was all based upon a falsehood. I wish I had an easy solution for you, but I don't.
You can try to go forward and hope that nothing comes out and proceed to get Lawful Permanent Residency and then later U.S. Citizenship, but that can all come crumbling down if some evidence or allegation comes out.
If she can get an annulment, that would be the best solution. If they say they cannot give her one because they find no records, then that helps, to just go forward, but there is still no guarantee.
Another option is to move to Malaysia and file for divorce there as long as she meets the jurisdictional requirements. US immigration
will not normally ask for previous marriage certificates but divorce certificates. So if she can legally get a divorce in Malaysia, then the U.S. would normally recognize it and she would be free to marry again and this qualify for a K-1.
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