So many emotions, it's hard to know what is the right thing to say. I think maybe your daughter thought that Friday was going to be her free pass and not getting out today most certainly took her down a notch towards reality. I'm glad to hear that she is making appropriate statements of remorse, and that you know that it isn't necessarily indicative of a great change on her part.
I wonder if the attorney had a run in with your difficult child before you met her, and that may have pushed her over the edge before you even got a chance to talk to her? difficult child could have said just about anything to her, so as awful as she behaved, it's probably best to not make assumptions about what motivated her to cut you short.
As to the DA, it might be best if you wait on contacting him until you and the SW have something definite in place. I'm sure he has a huge caseload, and will be happy to hear about the plan once it's in place, but he probably doesn't have time to go every step of the way with you to get there.
Terry's right. Take some advil and a warm bath. Give yourself a day and an evening or so off from this. There is nothing that you can resolve this weekend. It seems like in the long run your daughter will not come directly home to you. So, maybe it's time to clean her room this weekend, and set some things aside for her. If you're up to it, and you think you all can handle it, maybe you can see her next week. You're not abandoning her, she is just living with her choices. She's not going to be there forever. And you can be sure that she isn't going to want to go back.
Stay strong, and take care of yourself for a bit. You need it.