so sorry you and your family are going through all this.
sometimes what you are doing.. trying to ensure her last moments are comfortable are the only things one can do in face of a determined addict.
in the end all one can do is offer the path that an addict can take to kick their addiction and support if they chose to do so.
but when they reject that sometimes all one can do is stand aside and wait for the end.
and yes hospice is a wonderful thing.