I know this is similar to How to Handle a Character When She Is Lying About Her Name but the situation is slightly different in where my problem lies.
I have a character who is introduced as Tabatha to the reader. However she changes her name at one point and the reader does not know. Other characters are constantly referring to a person called "Maria" and the reader never 'sees' her in any scene. Later it is revealed that Maria is actually Tabatha (both to the readers and the characters who know her as Tabatha).
It's at this point where I run into my problem. She's embraced the new name "Maria" and she spends the bulk of the remainder of the narrative around characters who refer to her as such. However now the reader knows she is Tabatha and for at least half of the book (if not more) the narrator has called her this when she is in scene. But after the revelation, it seems fitting and appropriate for the narrator to call her Maria from this point on until she makes the conscious decision to change her name back.
That seems to be the right path but wanted to make sure it made senses
Also I want to be consistent considering I have another character who is often referred to by two different names. Only that scenario is different. I have a character who is almost always referred to as Mrs. Coles by the narrator because for the most part she is only around teenage characters who call her that. But during the rare scenes where she is around only other adults who call her by her first name "Anita" the narrator refers to her as such and typically each scene she's introduced by her full name and then it's subsequently shortened to either Mrs. Coles or Anita depending on the scene.
With that in mind, it almost seems that with my Tabatha character, if she is in a scene interacting mostly with people who ONLY refer to her as Tabatha that the narrator should adjust accordingly and when she is primarily with people who ONLY refer to her as Maria the narrator should adjust accordingly and just like with Anita Coles, at the beginning of each scene I introduce her in a way that gives both her names (not sure how I would do that) and then "shorten" it to whatever is appropriate for the scene.
For some reason though, that logic seems less appropriate with the Tabatha character than it does with the Anita Coles character (perhaps because it's easier to introduce Anita Coles to a scene by her full name and just shorten it).
I hope that's enough information to help with figuring this out.