“To be clear, I am supporting your decision. I believe you are confusing the word fight with argue. Negotiate might be a better term.
My understand of the process: The first step in negotiation is your proposal on what you think would be a kind and thoughtful agreement. The second step would be reviewing, and giving you my counter proposal. We repeat those steps several times. If we get stuck, then we hire a mediator to help resolve the differences.
Regards, Rock”
If I agree with this logically and it makes sense for me then I can tell her I am supporting her decision to work on a separation agreement. And lay out my understanding of a healthy process to negotiate.