LANE you said way too much in the phonecall. Remember, you want to use as few words with her as possible. If she says something informational, validate. If she asks something, answer her in as few words as possible. If it is a yes or no, simply say yes or no.
I am not sure what you mean by "cancel" the cabin reunion. Do you have to be there because it is your sister's cabin? I am torn on this one. Do the attendees know you are divorcing? Do your kids know? I think if not, then I would move forward with it and just be present, pleased, upbeat, but detached from her. If the attendees know, and if you've already told the kids about the impending D, then I see no reason for you to attend, and if that means it has to be cancelled because it is at your sister's cabin, then cancel. But I would wait for others to weigh on this since the timing is a bit problematic especially if you haven't been informing people of the situation yet.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018
