I was hoping to hear from you before now, because without any additional information from you, I would only be able to make an educated guess. However, I have experience with Drug Courts and will provide you with an answer. You can reply here on this question thread with any further clarification or follow ups that you may wish to provide.
Your girlfriend is in drug court, and she hadn't been able to get clean. If she keeps on in that direction, as you are probably aware, she will end up in prison. She did stabilize and was allowed to move in with you but then she was placed in a program.
Drug treatment programs expect recovering addicts to avoid people, places and things which could trigger them to reoffend. I'm betting that they see your relationship as a possible problem right now, since you were unable to keep her from using when she was not on probation. At least until she stabilizes so that her program trusts her judgment, she will be required to stay away from you and you from her.
You don't get a hearing if you're not a party to the case. However, SHE is entitled to bring this matter up before her counselor, the treatment court team and the judge to get them to changer her mind. Somewhere along the line, they will allow contact again, but in my experience, she will have to earn that.