I'm in agreement with everyone else - no need for you to pay for rehab yet again.
In terms of "culminating in heroin addiction and possible (inferred only by a counselor) cocaine use", count on it, she has very likely used it. Non addicts have a hard time believing this, but cocaine is actually a "soft drug" compared to heroin, other opiates, meth or for that matter, alcohol, all of which have much more severe withdrawal symptoms and are more deadly.