Okay so explanation for the Christmas special
I know (y/n)'s tone is supposed to be more set towards the 'idgaf' kinda personality, but because of how long she's been with the trolls now to which she considers her close friends, her personality dies down and becomes more real. This is the reason because firstly, it's the Christmas season and it's the first one in years that she actually got to spend this Holiday with the people she appreciates, and throughout the story her personality is supposed to become more softer the more she spends time with them.
And I know the personality change is kinda big from the latest chapter (9) to the Christmas special, but the reasoning for that is because that special itself doesn't go with that chapter which is fairly obvious. The special would go after the LAST CHAPTER to which I'm still planning out and brainstorming new ideas, and by then you'll see the development of how (y/n)'s personality and how she views the trolls comes to be.
but yeahhhhhh
no more (reader x Branch) for the rest of this book, the Christmas special is all you're gonna get :)
(Maybe)