Wow, FireWalker... .I feel so bad for your daughter and your family (and you!). I can't tell you what you should do--only you know yourself and your daughter well enough for that--but I
can tell you what
I would do (and
have done in a similar situation). I would go get her, and then guide her to the rules you have set up, telling her that she will be going to the DBT session and then you guys will go from there... .
There are a few reasons that I would do--and have done--something like that. Right now it was probably devastating for her to call you and admit her failure; she is also ashamed and beaten down, and admitting that was very hard for her. She is in a terrible place, and will be very thankful to you for coming to her aid. And now that she is in this mind-set, she is more likely to take your advice to save her life. At least that is how it worked with my own BPD son, when he was in a situation like that.
There's an Article that is incredibly insightful and helpful, and will give you some very good ideas on how to approach this:
Supporting a Child in Therapy, even if she is not being treated at this time. Also, here's one that will also give you insights and practical advice regarding encouraging her to go into that DBT therapy:
How to get a Borderline into Therapy.
The main thing is to remember not to order her to follow your rules, or to go to Therapy. You need to work this out with her as a collaboration, where she feels she has a say in her future. Being firm in what you are expecting for her to do, but compassionate in helping her to see that this is all in her best interests.
When solving a family member’s problems:
a) involve the family member in identifying what needs to be done
b) ask whether the person can "do" what’s needed in the solution
c) ask whether they want you to help them "do" what’s needed. Problems are best tackled through open discussion in the family. Everyone needs to be part of the discussion.
People are most likely to do their part when they are asked for their participation, and their views about the solution are respected. It is important to ask each family member whether he or she feels able to do the steps called for in the planned solution. By asking, you show recognition of how difficult the task may be for the other person. This goes hand in hand with acknowledging the difficulty of changing. You may feel a powerful urge to step in and help another family member. Your help may be appreciated or may be an unwanted intrusion. By asking if your help is wanted before you step in, your assistance is much less likely to be resented.I encourage you to read both of those Articles (the info above was taken from the first one); they are especially appropriate for you with this situation... .And if it were me, I'd be picking her up right now, and once I get her I'd hug her so hard she would know that I love her and care about her situation. I wouldn't argue, accuse, berate or humiliate her in the car... .She's feeling awful enough as it is; now is the time to be compassionate and loving and not angry and accusatory. And read the Articles before setting up the future for her; the DBT session isn't until Tuesday. You have a day or two before you have to let her know that she will be going (there shouldn't be a choice for her; you can "collaborate" about that with her after learning how).
You can do this, FireWalker... .You love your daughter and she needs your guidance right now. Her life probably depends on it