I honestly believe that The Queen is trying to outlast her son Charles. Wait until he has actually died, or is old enough so that spreading rumors of his ‘Tragic and Rapid Deterioration, no doubt due to the onset of Senility’ will be easily accepted. One month (one week?) after Charles is taken out of the lineage, then Elizabeth steps down, and then hands the crown to Prince William.
Are there actual provisions for that or would he have to waive his right?