I'm not sure what you can do. We'll leave that up to experienced SR folks.
The main thing is to remember that it's not your fault, that you have no control over it. She won't quit until she's ready to quit.
That said, you can tell her what you think and feel, how it's affecting you and your family.
You might look into 12-step meetings for family members and set some firm boundaries.
I wish you well.
Jane