Elizabeth Tudor was, not unreasonably, known as
Gloriana though I don't imagine it was ever abbreviated. I find
Gloria hubristic in spite of
Frances the badger's baby sister, so I'd welcome almost any name that wasn't it or close to it.
Elizabeth is decently distant.
Anyway, anything can be a nn for anything else if it seems to fit. I was at school with a very pleasant
Mary who was known as Porridge. Nobody remembers why.