I suspect that he could order her arrested as a material witness in an investigation.
I think he will put out an order to have her taken into Protective Custody. He probably already has a deadline set and if the courts to not do something by that deadline he will step in. I believe that the next 24 to 36 hours will be very interesting and I believe he will step in if the courts do not.
He could take her into protective custody BECAUSE of the denial of food and water by natural means. It would be his duty as the chief executive to prevent a forcible murder in progress.
He could also arrest her, as you say, as a material witness to an investigation.