#1 Well, you would have to find evidence that the marriage must be reported to NY authorities in order for it to be valid. It seems that USCIS has determined that NY recognizes it without the imam having to have reported it. So that would be one argument that you could make when responding to the RFE. But you have to find the law that supports it. You would need to perhaps post in the Family Law section on Just Answer and ask for a New York specific attorney.
#2 I doubt that they would accept this. You can try as a backup argument to #1, but I do not think it will work. That it be voidable helps, but I believe immigration will just say that even if you voided it, it would be now and would not date back to when you married your current spouse. Again, you can try and make the argument because you do have to respond to the notice of intent to deny.
#3 Unfortunately, they don't have to prove anything. Your spouse is asking for the benefit. The burden of proof
rests on her. I know that you think to yourself that if she had just not said anything, you would have your approval and you might be correct, but that is very dangerous. Imagine if years later she has U.S. Citizenship, a full life in the U.S., then someone who doesn't like her, wants revenge against her for something, or maybe doesn't like you and wants revenge against you and knows about this issue or discovers it and they report it to immigration, she could lose everything.
Fortunately, you have the way to solve this, it is just very inconvenient. Of course, don't give up and try these arguments to fight the notice of intent to deny, but if it doesn't work out, you still have the fall-back solution.
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