My wife's sister was has been issued a K-1 visa which is in her German passport. Once she enters the US under this visa, she has to marry her fiancé within 90 days and then submit for a Change of Status before receiving her Work And Travel Authorization documents.
Since this process can take several months, she wants to instead enter the US using her German passport under the VWP (Visa Waiver Program), then take an early vacation with her fiancée to Jamaica, again using her German passport to enter Jamaica. On return from Jamaica to the US, she wants to enter the US using the K-1 visa in her passport, then get married and submit for her change of status.
Is this possible? Can she enter the US under the VWP using her passport even if there is a valid visa in it, effectively choosing not to use it on that entry? Is there a requirement to use a visa on first entry to the United States if one is in your passport and is unused?
I don't know of any such requirement but need to find information on this. It seems to me that this should be possible as long as her visa is still valid and has not expired before she gets back to the US from Jamaica.