My brother and his kids joined us and we all had a blast. The kids only get to see each other a few times a year, but when they do, they make the most of it. We didn't have spectacular weather part of the time we were at Glacier, but the kids didn't mind!
I am already excited about a trip back there. It's the kind of place that you just can't get sick of. There is too much to see, and too many places to explore. (Picture overload coming up!)