You have tried everything, by now you're learning that none of it works. There is nothing we can do to make an A want to get sober. There is nothing we can say that will get through to them. They will pull out their bag of tricks that work so well on family: crying, depression, "leave me on the streets", "I just want to die", complain about AA, complain about a shelter, complain about treatment, etc etc etc. We'll be told that it's our fault, that we don't love them, how can we leave them like this. Etc Etc Etc.
At some point we have to get out of the way, and let their Higher Power take over. We have to give them the dignity to make their own choices, even when we hate their choices. Don't get pulled into her bad choices. Allow her to experience the full consequences of her choices. Take that energy you've been putting into your sister, and put it into you. Start loving yourself as much as you love her. Find an AlAnon group near you, it will help you and make your days easier. Hold your boundaries. You are entitled to live your life. Prayers and Hugs to you.