While the outlet says it's "unclear" what role Lilly would be playing, according to the article "some insiders" say she'd play the daughter of Hank Pym (Michael Douglas) and the love interest of the film's lead character, Scott Lang (Paul Rudd). This would be a departure from the comic books, since Hank Pym doesn't have a daughter in the Marvel source material. Given the 25-year age difference between Rudd and Douglas (Pym and Lang are depicted in the same age range in the comics), it's clear that director/co-writer Edgar Wright and co-writer Joe Cornish are willing to diverge from comic book tradition.
The natural expectation for comic book fans is to presume any major female character in an "Ant-Man" film might be The Wasp -- a founding Avenger, and Hank Pym's long-time romantic and crimefighting partner -- but the character wasn't mentioned in Variety's report. The Hollywood Reporter states Lilly's role is "not intended to be a one-off appearance."
Best known for her role as Kate Austen on all six seasons of ABC's genre TV sensation "Lost," Lilly also appeared in 2008 Best Picture winner "The Hurt Locker," and played elf warrior Tauriel in "The Hobbit: The Desolation of Smaug" and its forthcoming sequel, "The Hobbit: There and Back Again."
Beyond Rudd and Douglas, Michael Peña was reportedly offered a role in the film last month. Marvel declined comment on Variety's report. "Ant-Man" production is scheduled to start in April, with a release date of July 17, 2015.