(((desperatesister))) welcome to SR! I'm sorry for what has brought you here, but it sounds as if you've been through this for quite a while. I think you were wise in your response, and don't think I'd be offering her help with living arrangements, either. I'm an RA (recovering addict) and have loved ones who are addicts. When we addicts truly want recovery, we find it.
I'm glad you've found us, and are going to a meeting. Your sister will find her way, in whichever direction she truly wants to go. This is a great place for ES&H (experience, strength and hope) from people who know what you are going through.
Hugs and prayers,
Amy