While I'm not sure about the trains sisters' drug use, and I can't attest to the status of their underwear, I do know that these girls have managed for the most part to stay clear of the normal trashy heiress route (hilton cough cough). Which isn't exactly a given if your mother is Danielle Steel and has made her fortune by writing trashy romance novels. If any of the young starlets were going to go the Hilton route, I would have guessed these two.
But they have stayed clear of the tabloids, instead becoming stars on the fashion circuit. They support established houses by buying amazing couture while at the same time have become friends with young designers like Proenza Schouler, Alexander Wang, and Catherine Holstein.