My sister's fiance passed just under 2 years ago from melanoma. It seems once the tumors take hold as in your sisters case hospice is the best thing you can do for her. There mission is to help not only her but the family understand the process that is taking place and to cope and to make your sister as comfortable as possible and given her some dignity in the process. I'm so sorry she has had to deal with all this. I will say a prayer for all of you.