Yup.. the more stubborn and in pain she is the more she's going to escape into teh addiction.
What kind of relationship do you have with these friends of hers?
Any success with her parents yet? Are you educating them well and keeping in touch with them?
You have to handle this the same way you would if she was gambling your households life savings away at a casino and such.. that means get parents involved and educate them... KEEP doing it until they are on board