Denied Reentry Permit for Permanant Resident

If your mother-in-law has been outside of the United States for longer than one year, then she will abandon that green card unless she applied for a reentry permit prior to leaving the United States. It may be possible to get a returning resident visa, but most likely she will have to reapply for a green card again. You should retain counsel to process the case from start to finish to make sure that it's done competently.    

This situation is an example where people have further complicated matters by their actions.  This is a textbook reason why an experienced immigration attorney ought to have been contacted sooner.  There will be things that must be done before your mother in law can be petitioned again.  Perhaps, she is now inadmissible. Whether, how much, and how quickly it can be done remain unclear, but it is likely to take much longer than your family will want.  Therefore, it is easy to fall victim to a questionable opinion or speculation. As a result, I strongly recommend a paid consultation by Zoom or in person, with an ethically considerate immigration attorney, so that decisions can be made in your families best interests before your family is further impacted by the situation that was created by the departure and subsequent actions.