According to Deadline, some scheduling issues* have been resolved and Jessica Chastain is looking likely to take the aforementioned role, somebody they say is “every bit as smart as Tony Stark.”
But every bit as smart-mouthed?
Perhaps most likely is that she’s a version of Maya Hansen from the Extremis comics. She’s, the creator of the nanotechnology at the heart of the story, and the one who calls on Stark when it is first acquired by terrorists. The two of them are revealed to have some kind of past, I understand, as well as some romantic dalliances that, if retained in the adaptation, could be somewhat convoluted by Pepper Potts’ ongoing role in the movie series.
The only other clues as to how the filmmakers see the character come from the list of other potentials lined up when Chastain appeared unavailable: Gemma Arterton, Diane Kruger, Isla Fisher. I guess the casting had to take care of the “sexy” part, while the script and white coat could take care of “scientist.”
*I think Chastain’s life must be one long string of scheduling issues. She seems to make six or seven films a year.