Autumnrain, it is good to hear from you, even if the news is not good. You are right--there is still a stigma attached to alcoholism, and even more so to IV drug use--even if it was 40 yrs. ago, as is the case with me. The only place I have not encountered that judgmental attitude is at Mayo.
Butterfly had a good suggestion about Hospice. From what I understand, that requires a doctor's referral. Does your sister have a hepatologist or even a primary care doc who is aware of her medical status? Also, you mention how large her abdomen is--has she been having paracentesis (draining?) I know that helps to relieve pain and pressure for a little while and some have to have it regularly.
Remember to take care of yourself through all this. My prayers are with your sister, you, and your family.