How much you want to bet that the father of the kids was working mostly off the books for the wealthy grandfather, fixing up the grandfather's properties for resale? Meanwhile the grandfather could pay for the grandkids education at the expensive private school
I share your suspicion to some extent (although I think it more likely that the wealthy elders were just subsidizing the youngers so they didn’t need to be in the real world worrying about money). If we are correct, these folks are stinkers and pretty damned arrogant to think they could get away with being so high profile.