http://query.nytimes.com/gst/fullpage.html?res=940DE5D6103AF930A35754C0A96E948260
Looks like granddad, Frederick G. Frost Jr., is VERY well off. He is a retired architect who headed Frost Associates, successor to the New York architectural firm founded in 1917 by his father, the late Frederick G. Frost.
Frederick has passed on. He’d be the 12 yo’s great-granddad.
Yes, from all appearances he did OK in life.
And it's VERY easy to hide income while doing real estate. Buy a house, spend time improving it, sell it. The money you made is capital gains, rather than salary from the work you put in. And if you trade up to a bigger house, you can avoid even cap gains tax