Kate did visit Daniel Radcliffe on the set of Harry Potter and the Goblet of Fire, thanks to the Make-A-Wish foundation.
"I first saw Dan while he was filming a scene with Alan Rickman (Snape), but I didn't have a chance to meet him then."
"I was standing literally two feet from Daniel Radcliffe himself! Dan got up, greeted us and shook our hands, but then he had to sit back down to have his make-up done. We talked for about twenty minutes straight about everything from school, to music, to sports! Once Dan's make-up was finished we all walked back to the set where he was filming with Alan Rickman, and they did the scene again. Between takes Dan would come over and talk with us."