She dropped weight and acquired a lot of piercings to portray the role of a hacker
The Rooneys and the Maras are two of the wealthiest Irish-American families, and Rooney Mara is the product of their union. The actress made her feature film debut as the title character in the neo-noir thriller The Girl With the Dragon Tattoo. To portray hacker Lisbeth Salander, Rooney had to lose weight and have multiple piercings.
He didn’t ask her to drop weight for this role, which was directed by David Fincher. Contrarily, she had expected this character to be skeletal. Because of this, Rooney has decided to keep some of his piercings in place in the event of a sequel!