My impulse (I am not being led by my impulses and whipped around by me emotions however) is to email her back in 24-48 saying, “please email me your proposal and I will look it over.”
At the same time, I have had some good advice from L to attempt to negotiate fairly in good faith with W an agreement and hopefully avoid an escalated expensive court battle.
I can see benefits to mediation and at the same time I am reasonably confident that I can ask W what things are important to her and I can express my values.