My DD 14 will be going to England for 3 weeks this summer. The family she is staying with is taking her to the Henley Regatta on the Saturday date. They just emailed me that she will need to have a knee length dress and a hat. Does anyone know how fancy of a dress it should be? Can it be a cotton sun dress or something much nicer. As I said she will only be 14, but she is a typical American teen who wears mostly short shorts and tank tops during the summer.