Thank you all, good responses.
I guess even in this I was getting caught up in worrying about whether everyone was getting along, having a good time, feelings not being hurt, etc. Worrying about others rather than even thinking about myself.
I started posting this seconds after hanging up w/my daughter and listening to her tell me why I shouldn't 'encourage' son to visit g'pa's grave w/family this weekend . . . she doesn't get invited to do things w/g'ma, me, my siblings, but my son does, etc. It seemed like there was maybe something I could say (or in a certain way) that would convince her to give brother a chance or at least be willing to be in the same place at the same time.