A bit of an over-reaction from W, huh?! But I think she was sensing the same thing I did - that you spent time in the kids' room to steer clear of the adults. Even if that wasn't the reason, I can understand how it might be perceived that way by a disgruntled W. Should you have done something different? Well, I've learned from dealing with XW that being aware of how things might be perceived is crucial in peaceful co-parenting, even if the underlying intent is valid. I'm not trying to give you parenting advice (God knows I need plenty for myself). Just relating my own experience.
I see your point G and I can see hers. I will say this not in defense of myself but a POV..she wrote everything down so I get the jist of what went on an was said in that meeting. This place is small, rooms are side by side. I know my way around it.
It was an opportunity to spend time with D and have fun..I am guilty of taking advantage of the opportunity.