speak; I'll go no further

I think it is generally considered advisable to shelter your kids from things like family finances. But I've been wondering, does that create a distance between parent and kid? When the kid gets older, is it difficult to have a meaningful relationship when one half doesn't express the weightiest things on his or her mind? Especially when the kid is old enough to know just enough to worry about it? Obviously I am thinking yes, subject to difficult questions like at what age do you start to share. But is it just too painful for a kid to recognize the parent's vulnerability and/or fallibility? Or is that just a symptom of the problem?