Scott, glad things went relatively well. I would caution you though, what I'm seeing here is a woman that is friend zoning her soon-to-be exH, and I feel you are seeing all of this as a sign you still have a chance of saving your MR. Maybe you do still have a chance but I'm not sure you should put expectations into naps, tears, and your SiL's words. Expectations will set you up for disappointment everytime.
Likely the tears and the nap were coming from the same place the fbomb and other kid unfriendly language came from: alcohol. And she likely used the alcohol to deal with an otherwise awkward situation.
Back on the DB horse. Now that this bad idea joint Christmas is past, time to move on with or without her to an awesome life.
BTW, love your answer to your neighbor! Now go put that plan into action!!
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018