Originally Posted by ksandness

Yes, as I mentioned above, it's easy--signage in all major train stations is multilingual (at least Japanese and English, and in recent years, Chinese and Korean as well). And you can check the schedule and reserve tickets for both trains at Kyoto Station.
Furthermore, my experience over the years has been that children absolutely love riding trains, and your ten-year-old is just the right age to enjoy riding one of the world's fastest trains and seeing the Japanese countryside and maybe even a long look at Mount Fuji if atmospheric conditions are right.
Another plane ride when you'll soon be on an international flight? Meh.