I am sorry to hear about mother's condition. There are some options that you can discuss with the family. She can ask her own doctor to get her on TPN, which can help her for some bonus times, in the meantime you can contact Clinical trial to see if she can qualify for the trials. My brother,51 yrs old, he had TPN and survived 8 months more, even though it was not a quality time, but it can buy time for more treatment in Clinical trial.
God Bless you and the Family,