Princess Diana made a shocking confession in the days before her death. According to a friend, the late Princess of Wales believed she made one major mistake regarding her sons, Prince William and Prince Harry. MORE: Follow Wonderwall on MSN for more top news Mirrorpix/Newscom/The Mega Agency Diana regretted the Panorama interview During an August 1997 trip to Greece, Diana allegedly told friend Rosa Monckton that she felt guilty about how her bombshell Panorama interview would affect her kids.