The video is available here, but here's what Kershaw had to say in response (via CBS Philly):
Hey Mo'ne, just wanted to say congratulations on making it to Williamsport (Pennsylvania). That's awesome; such a cool thing for you to get to do, such a fun opportunity. And I heard you're ready for a pitch-off. I don't know exactly what that means, but I'm prepared. I'm ready for whenever you can make it out to L.A., just let me know.
It's great that the Dodgers ace took a moment to respond and congratulate the young lady. But Kershaw better be careful: That girl has some serious stuff. Here are some highlights and a profile of the dynamo pitcher: