Legal Question in Criminal Law in Florida

Yes, absolutely she can be arrested. Selling stolen jewelry to a pawn is illegal and constitutes at least 2 different crimes. The first is dealing in stolen property, a 2nd degree felony punishable by up to 15 years in prison, and false verification of ownership to a pawnbroker, a 3rd degree felony punishable by up to 5 years in prison. Of course, there could also be a theft charge or others depending on the allegations.

If your mother in law gave your wife the rings then that is a defense, but it will essentially come down to who the jury believes. If your mother in law is threatening to tell the police that your wife stole them then there is a good chance she will at least be arrested.