In The Lord of the Rings Gimli refers to Galadriel as 'Queen Galadriel', and she is again referred to as a Queen in Of The Rings Of Power And The Third Age.
Of course Tolkien wrote elsewhere that Galadriel took no title of Queen (Unfinished Tales) and in his response to the Zimmerman film treatment (in a letter), he noted that she was not a Queen.
So which is it? I look at the sources first. Queen Galadriel was published by JRRT himself, plus another reference published by Christopher Tolkien (Of The Rings Of Power) in the 1977 Silmarillion -- concerning which, consistency with texts already in print was part of the approach -- in other words, seemingly Christopher Tolkien saw no great reason to revise this statement for The Silmarillion...
... notes never published by the author, although admittedly written later than The Lord of The Rings or Of The Rings Of Power, and at least one letter (at the moment I don't recall if there are any other statements concerning Galadriel not being a 'Queen', but maybe there are).
Arguably Tolkien could claim that Gimli, as a character in his story, was technically wrong, even though Gimli himself had been to Lorien. And JRRT could have revised Of The Rings Of Power on this point (or implied it too was incorrect), although apparently he never did, for whatever reason.
In any case this is a good example of what the posthumously published texts might inject.