I have never been to a Inpatient Rehabilitation Center myself, although I probably might be going here soon maybe.
I've basically done the AA Way and of course Narcotics Anonymous, but I use all sort of things like tapping, outdoors, but if you want you might suggest if this is possible maybe going with her to meetings for a few weeks everyday and than go from there. If she wants to stop than it will work, but if she doesn't want to stop, trust me there is really no one can do.
best wishes