I think this kind of proves the point, though. These kids know their entrepreneurial and business-minded parents from birth (i.e. "what they know" comes from "who they know"), as opposed to those of us who grew up as children of "salary-parents"

Great counter point - people tend to discount parental influence as being "who you know" if it isn't direct nepotism. It's essentially like being born with a fantastic mentor from Day 1, and those of us fortunate to have that spirit of embracing entrepreneurial pursuits from a young age are, well, fortunate.

I've always heard the "who you know" used as a way to state that contacts are more important than skills, but as you point out, a good mentor blurs the lines between them.

You mean like the rest of us "wage slaves"?

But that supports the "it's not what you know, it's who you know." idea. Most people I think see that saying as meaning that if you take somebody, like this girl for instance, and swap her out for somebody else who didn't accomplish anything like this, that the new person could more easily be similarly successfully to this girl.