6 She exposed her kids to a non-royal way of life.

It wasn't just school where she rebelled against the constraints of royal childhood. Diana took the boys to get hamburgers at McDonald's, rode the tube and the bus, and let them wear jeans and baseball caps; they white-water rafted and rode bicycles. At Disney, they stood in line like everyone else.

She also took them to hospitals and homeless shelters. "She very much wanted to get us to see the rawness of real life," William told ABC News' Katie Couric in 2012. "And I can't thank her enough for that, 'cause reality bites in a big way, and it was one of the biggest lessons I learned is, just how lucky and privileged so many of us are — particularly myself."