I am so sorry for everything you have been and continue to go through. Addiction is one of the hardest things, it not only affects the person (and in her case her unborn child) but it really affects everyone around them too!
From skimming over this thread I had a few thoughts. First of all, you've done a great job doing everything you can and do what you think is best for her. She is
VERY lucky to have you in her life. Many people with addiction problems aren't that lucky and have no one for support. That said it does seem apparent that you're at your whits end, that she doesn't seem to appreciate what it is you are doing, and there seems to be an endless cycle of bad going on.
The rehab that she's in, it's wonderful that it's long term and free. Unfortunately it may not be meeting her basic needs. What makes this a rehab? Just basic rules that she can't use? In reality she needs SERIOUS therapy (be it individual, group, or specific types like cognitive behavioral therapy, etc.).
Before I say anything else I just wanted you to know I'm in social work. While I haven't specialized in Addiction I have had some exposure/education about it and peers that are in this field. So while I'm not an expert I do have some minor background knowledge on this.
The most important, yet hardest, thing to keep in mind with addiction is that a person will
only change when they decide to. I know of people that have hit what everyone else sees as rock bottom (loss of job, house, family, etc.) yet they have not viewed this as enough of a loss to do anything different or want to change. Whatever it takes for a person to decide to change their ways is what's needed, it's not the same for everyone. Additionally, when you keep that in mind, a person in rehab because someone
else made them or strongly encouraged them has a really high failure rate. (Could be court related or just pressure from family/friends.) Keep in mind many people go through several stints of rehab, and only when they decide to change themselves will they actually have success. (That and relapse is expected as it is part of the recovery process.) Addiction is seen as a
brain disease. While it gets old fast to people around them, it is something that takes a lot to change the cycle and become healthy.
If she is in a good rehab facility she'll get the help she needs (if she's willing to take it and work hard on changing things). That would include working on eventually fixing social issues. Hypothetically a great facility would be a one stop shop where when a person completes their program they could then go on and try to mend things in the oustide world. That said, if this is not a great facility she could be lacking some of the help she really needs. (Also keep in mind many persons that deal with addiction/dependency have a dual diagnosis, which means they also suffer from something else--Depression or some other mental disorder.)
It may be essential to make sure this is the right facility for her. If it is then it may just be appropriate for you to turn over your responsibilities to this facility. They should be better equipped to handle such a situation. Clearly though if this facility isn't all it should be then that wouldn't be a good idea.
That's all I've got for now. But hopefully that was of some help. Truly this is a difficult situation no matter how you spin it or what you do. Know that you've done what you feel is right and she's lucky to have someone that cares that much in her life. But it would be of use to consult a professional, someone who works in the addiction field. They can assist you in the issues you're having and in helping you figure out what's best for your friend.
-Vicky
P.S. While I was working for the Florida Governor's Office of Drug Control I came across this pamphlet, which is really great.
Addiction: "Drugs, Brains, and Behavior - The Science of Addiction"