Some fine thoughts from others in here Bowdude. It has to be hard...I've been through this with a few friends and their kids... there is always that inner question for many parents of: Did I do something wrong?
Addictions are rammifications of bad choices ...and nobody can choose for another. God gives free choice...with the promise that when we choose to "redecide" He stands with open arms ready to rebuild and forgive.
Arkiewoodsman said it about the best I've seen... stand firm, don't enable, but be ready to forgive and try, try again when she comes to ask...but get counsel on how best to help that will help and not enable.
God will provide...but it has to be Autum's choice...
Just hit me ---how hard all this advice might be to live out...to be so "unconditional" in our human love when an adult childs hurt us so deeply...but then I smiled thinking, "Wow... This must be how Christ feels every day with each of us...and our recurring bad choices..."
Keep the Son in your eyes!