Unlike the short royal courtships of the past, Prince William and Catherine dated for nine years before their engagement. Sarah says this should help Catherine in the palace. "Diana had a few months before she married Charles. I had like two dinners and one weekend. It was very different then: We weren't allowed to live together. We weren't allowed to be seen staying the night and things like that," Sarah says. "As the Prince of Wales said, [Catherine] knows the ropes. They're such a great couple together. And I pray that from Diana and me, from our mistakes, they would have learned. We've trailblazed for them, I hope."