While Hermione might not be directly responsible for the Christmas magic that is currently affecting the entire Nexus plaza, it was her return back to her world that might have influenced all the miraculous magically events that are currently being demonstrated everywhere.

And Hermione is enjoying every second of it. She is wearing a festive Christmas sweater. Close by the witch in question is Crookshanks, who is also dressed for the season

One can find Hermione exploring all the goodies around the Nexus Plaza. And if anyone is curious about some of the treats that they discover, they are free to ask her.