According to IMBD it has stars resumes of movies they have been in or are appearing in. In the filmorgraphy section it says Twilight Sequel: New Moon and above it, it says Justine Wachsberger as Gianna? So maybe she will be playing that part, maybe not……. If you’d like to see her profile thing on IMBD click Here.
Here is my description of Gianna’s role in New Moon:
Gianna works for the Volturi as a receptionist. She is tall and has green eyes. She knows that one day she will probably be killed by them, but she hopes that they may reconsider killing her when that day comes and turn her into a vampire.
She fits the part