Your shared ancestors; Buer; her own Higher Self (accessible through evocation or core shamanic journeying, I can teach you this method); construction, at a pinch, of an entity to possess her and keep that crap from drawing her back in.
She’s probably is so much pain when she’s not on those things, and knows she can relieve that pain any second just by having one more, managed, this-time-I-can-control-it (or “Fuck it, I’ve screwed everything up”) session of using.
And sobriety’s not a moral matter, or a matter for willpower or smarts - it uses every resource against the person, so the stronger she is, the stronger the urge to use; the smarter she is, the more clever its arguments to go back to it.
I’m making this point to illustrate that she’s like someone with a bleeding wound, it needs some kind of energetic patching to stop the flow of energy and mental preoccupation back towards the stuff.
I’ll PM you the first part of the core shamanism tutorial, I can speed you through that or if you can evoke, you could evoke her Higher Self, also lookup Buer on here, and the thread below has a simple method to begin constructing a servitor - there are energy healing methods you can use later once she’s been clean for a bit and is getting used to it: