Yes, go BACK and talk to your W and tell her to BACK OFF.
Consider this. You tell your W that you want her to choose where to live. In actuality, that's not true, you want your W to live with you. So when she chooses to leave, you feel you need to take things into your own hands. You contact her boss and tell him/her what is going on and tell him/her that your W needs to be spoken to. Or... you contact a counselor. And you force your W to see that counselor. This, all in hopes, that your W will feel better and come home to you. Sounds like a plan, right?? I mean your W would love that and this would yield good results because, of course, this is for your W's own good! It's a recipe for disaster. And I am not really clear as to why people think that children feel any different.
Your D might need counseling. But she cannot be forced into it. Let me restate, she can be forced into it, but it won't yield the results that W is hoping for. And having that occur at school is really invading her "safe zone." There's a better way. Which I think you agree with. JMO.