Now which grandson??
My wife follows the Royals. Her money's on William.
The line of succession is set by Act of Parliament, the Queen cannot Change it.
https://en.m.wikipedia.org/wiki/Succession_to_the_British_throne
Queen doesn’t get a say. Not officially.
The theory is that Chuck would agree to step aside. Second in line is fixed (and pretty much has been for a couple hundred years), and it would be William.
I doubt the Leftist kooks in charge of the UK have any problem with Charles. He’s one of them.