Turtle is a graphics module that has been written in Python, and is an incredible starting point for getting kids interested in programming. It handles all the complexities that come with graphics programming, and lets them focus purely on learning the very basics whilst keeping them interested.
It is also a very good tool to use in order to demonstrate event-driven programs. It features event handlers and listeners, which is all that we need:
window = turtle.Screen()
window.title("Event Handling 101")
nathan = turtle.Turtle()
if __name__ == '__main__':