Your plan to not negotiate with Ws lawyer sounds good to me. It seems too easy for W to detach from the damage she is about to cause by having her attorney handle it for her. I'm amazed that our legal process can be so detached that the people involved in a sitch can hire third parties to solve their problems for them, having her lawyer talk to your lawyer.
The damage D does is real, and eventually your W will find that out. I'd say the more her lawyer talks with W about the D or S, the more ownership W will have to take, and hopefully the sooner she will begin to see the damage she is about to cause.
My W set up several appointments with a Lawyer to discuss D or S. I told her I would not go, and didn't. She went and never followed up. Force the ownership onto W, and KOFTGF. I wouldn't approach negoations with W's L at all - but you're the lawyer.....
About your blabber mouth I've struggled with what to tell folks about our sitch, but these are people that don't even know anything is wrong. I decided two things: 1) I am going to be honest with myself and others, and tell them my relationship with W is bad. No details, just "not good." or "really not good." 2) I am going follow that up with a request they please pray for W and me. (As faithful and spiritual as I've been on the BB, I do not represent Christ that consistently in person, and have been strongly convicted I need to do a better job at that.)
You are in a sitch where people are coming to you for the truth. They already know something is up, and want the straight scoop. If it ever gets back to W, as long as your "defense" can be, "I didn't tell them anything they didn't already know, I just confirmed it was true", I think whatever you tell anyone is up to your estimation of their interest in you. Besides, if you only confirm their beliefs, I don't think they are going to run back to W and tell her.
I don't think you're running around blabbing to every local figure you meet. You were just asked and the lid blew off the pressure cooker when they cracked it a little to look inside.
