If the Feds have gone through the civil forfeiture proceeding (which is necessary to seize the real estate), then the current occupant has until--and unfortunately, only until--they bring a legal action to remove her. Once the property has been legally taken by the Feds, any occupants have no more legal right to remain; while she would have to be removed in a court proceeding, that proceeding can be instituted at any time. There is is no way to predict how long that will  be, since it depends on when the Feds decide to take action, she is subject to removal when the Feds choose to act.