Originally Posted by MARG
I don't think you will find "Lillibet" on her birth certificate. It is, of course, a diminutive of "Elizabeth".
There is absolutely no comparison.
Of course there is - one is the name by which they were known in their family - David, Bertie (not Albert by the way) and Lillibet whereas the other is the name by which they chose to be known on becoming monarch - Edward, George and Elizabeth. Had Elizabeth wished to be known as Queen Lilibet there is nothing that says that she couldn't. The monarch doesn't have to use one of the names on their birth/baptismal certificates. They can chose any name they like.
They could have chosen to use, as their regnal names, whatever they wanted to and they chose. The names they did chose were different to the ones by which they were known within their families and private circles but that was their choice and therefore wouldn't have contributed to any identity crisis.
My point is that any changed name between the more commonly used name in private, and the official name, was made by them. They were still called by their pet names at home and only used the official name in official capacities.