Actually it's not a silly question if by 'met' they meant have you been close enough to William and/or Kate to say hello on one of their many walkabouts. I know several people who have 'met' the Queen in this way, though they couldn't claim to be close friends.
I hope we continue to get many US vistors to the UK. They are a masive boost to the economy and all those I've met have been extremely polite and incredibly enthusiastic.