OP you are in a unwinnable situation, and I feel for you...
BUT....what the above poster says about the CRIMINALS that surround addicts is very important for YOU to understand.....
What happens when your sister starts complaining to her "friends" that her sibling is controlling what to HER may be a fortune....I would NOT want to be in your shoes. Drug addicts are scary people who will do anything to get money for thier addiction. I would not put my own family into this mess.
Either give up being responsible for the trust, or get ready for a possible raft of S****. In all likelihood, a long time addict's brain is ruined and will never be the same. If she's railing and violent NOW, what happens when she's whining to someone "Well my sibling has my inheritance and won't cough it up-let's go over and see if we can make him...."
Please take my advice. I have a mentally ill brother who I've tried to "fix" for 45 years. It will NOT happen. I still worry about him when I lie awake at nights. His brain is ruined. His life sucks. He is 70, and is in assisted living which is based on SSI and a small VA pension. I tried having him live with me for a while and it was a nightmare. I KNOW he'll never be normal, and I can't fix him, but that doesn't mean I don't have remorse over his wasted life.
Also, he could NOT inherit, or he would have lost his spot in this place, which would have been a disaster.
My brother is lost in a world of paranoid delusions, and I have long since stopped thinking HE wants to live a life of "normalcy". He cares NOT about his hygiene, surroundings, the outside world.
He is in his own world, and for YEARS I tried to mold his life into what I thought it should be. I won't even go into what it did to my Mom.
A drug addict with years of use is probably the same. The ONLY thing they care about it the next fix. A lay person can not even begin to heal her.
Please don't get between the addict and a pile of money. It will not be worth it, and YOU will suffer WAY more than your sister ever will. It's one thing to be the "bad guy" to her, but please think about the creeps she surrounds herself with every day. As for giving her a book...might as well give one to your dog-it'll get more out of it.
Good luck.