Since the Jubilee, the “wonder who the next King will be” crowd have been spinning their web of theories. Most are agreed that the Queen will not step down. There are constitutional questions in this as well as the specter of electing a king which would undercut the effectiveness of the position in its present form which has withstood the test of time.
Above all of the theories is one element that is beyond our ken and control: God – fate – whatever you wish to call it. We cannot accurately predict the outcome. The Queen may live long enough for the next two generations to expire leaving a baby on the throne! Here is one article of many on the subject. Enjoy and imagine with the rest of us. It makes a good chess game. And here is another and, why not, yet another.