Bubbly? Sounds like the other gps and the children are both more outgoing than you, and I find such people often do not see or gravitate to people who are less so. It's not about your adequacy; it's just social stratification. I can see it would be painful.

I don't have any experience of your situation specifically, though. I have no kids, nor did I ever know any of my grandparents, for geographic reasons.