She needs to get out of this fast with the help of an immigration and possibly a criminal al defense attorney so that she doesn't get prosecuted. Get an attorney before filing a complaint with ICE.
She does need to hire an immigration attorney first think in the morning.
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I strongly suggest that your GF notify the UsCIS that her spouse married her in order to obtain a green card and that the marriage is a sham. She does not want to be charged with marriage fraud which is a federal crine and can mean a fine and/or prison time.
All she has to so it not show up for the interview. I suggest she file for a divorce.
It sounds as though your girl friend is a U.S. citizen. In that case, the case can probably be resolved though either withdrawal of any petition she has filed or though divorce. She should consult with an experienced immigration attorney for assistance.
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