Addiction is an epidemic. Nothing you say or do, or not, is going to get through to her...get or keep her sober. You are not that powerful. None of us are.
Until she experiences consequences, there is no hope for recovery. Just when we think he/she is reaching bottom, addicts/alcoholics tend to keep on digging deeper.
Do not, under any circumstances, give her money, do for her what she can do for herself and watch your stuff.
Many have found Alanon helpful in times like this to learn how to cope and control their own reactions to people, places and things beyond their control.