In her book she says that her manager, when she got one, told her to do TV and the movies. I don't know why. She's just another face in the crowd when she plays roles that don't show off her talent. And when she takes on a role in something like "gcw" or whatever, it can set her back.
I do want to watch an episode or two of Pushing Daisies, the show that she won the featured actress Emmy for. It sounds really bizarre, but it might be just a fun show, and she says she got to sing in it.
It's in live theater that she shines. She's a very talented comedian with a world class voice (and by all accounts a very sweet person). Very few can play Lilly Garland and Cunegonde as well as she can. These roles are what she'll be remembered for. Remember that she got rave reviews from every critic, even the London critic who had to apologize in advance to his London following for all the nice things he was about to say.
BWW published an interview that Elaine Paige had with her at the final rehearsal for hosting the Tonys. The rumor was that 20th Century would be relocating to the West End and that KC might go there with it. She corroborated the rumor. Said she loved living in London only second to New York. She might get the respect in London that The King and I and Fun Home kind of deprived her of in New York.