I reply that i have relayed message and "encouraged" kids to join her, however I have not spoken to my family about any plans other than Thanksgiving day.
Just want to clarify -- does this mean you included in the message that you have not spoken to your family about any plans other than Thanksgiving?
Her last email comes across that she would appreciate if I would tell my family (mom, sisters, brother in law, nieces, nephews) not to make any plans that would compete with her time planned on Sunday morning.
I think if you've already responded, then no further response is necessary. Even with a custody situation in play, you have met the minimum requirement for reasonable communication.
It seems like there is often a messy stage after divorce when one or both parties are still disentangling, and it gets played out around kids and family obligations. If you have strong values about the kids spending time with their mom, that's between you and the kids. But if you are done, detached, and don't-let-the-door-hit-you-on-the-way-out, then radio silence is totally appropriate. It's not reasonable for her to dictate to you what your family does.
Option 2 is about vindication. I no longer trust that feeling because it's a form of negative engagement. It might feel good to put her in her place, but it's still engagement.
Also, just an observation. I noticed my ex really dysregulated around holidays after my divorce, almost like clock work. Your ex may be experiencing wacky stuff because holidays can do that to people, and she is feeling bent even more out of shape because of her BPD traits. The best thing you can do for yourself is to lay low and not engage so that
you can enjoy the holidays. She'll learn over time that you can't be rattled, and isn't that what you're really going for?