Can my mother sell gift received from my mother in law

If MIL (mother in law) get a gold neckless from my wife's parent's at the time of marriage as a gift, and after few years (7) later due to high risk operation she sale the neckless due to medical bills, is she commuting any crim? Or if later can they hold her accountable or if they ask to return the gift and she cannot then is she hold for the same?