As of now of what she's filmed it looks like she has one scene

hopefully that changes. That Jason dude keeps replying to hilary fans.
I can't take all this secrecy
EDIT: deadline.com has mentioned the film, saying Veep start Timothy Simons is attached to the film
EXCLUSIVE: VEEP star Timothy Simons is joining Joaquin Phoenix, Reese Witherspoon, Owen Wilson, Josh Brolin, Martin Short, Katherine Waterston and Jena Malone in Paul Thomas Anderson‘s Inherent Vice, an adaptation of Thomas Pynchon’s 2009 detective novel. Shooting is underway for the Warner Bros pic with Anderson producing through his Ghoulardi Film Company along with JoAnne Sellar and Daniel Lupi. Simons is certainly busy. He’s also taken on a role in Ivan Reitman’s Draft Day
and a supporting turn in the Bobby Castrone indie comedy, Flock Of Dudes before he returns to shooting the third season of the Emmy-nominated HBO show VEEP. Simons is repped by UTA, Untitled, and Derek Kroeger at Felker Toczek.
http://www.deadline.com/2013/07/veep...inherent-vice/