Mara has Irish roots on both sides of her family. Her "Rooney" ancestors originate in Newry, County Down.[5] Through her maternal grandmother, she is also of Italian descent.[6][7] Her paternal grandfather, Wellington Mara, the long-time co-owner of the Giants, was succeeded in that position by her uncle, John Mara. Her maternal grandfather, Timothy James "Tim" Rooney, has run Yonkers Raceway in Yonkers, New York since 1972.[8][9] Mara is the great-granddaughter of both New York Giants founder Tim Mara and Pittsburgh Steelers founder Art Rooney, Sr.[10] Her great-uncle, Dan Rooney, is chairman of the Steelers, the United States Ambassador to Ireland, and the co-founder of The Ireland Funds charitable organization.
After graduating from Fox Lane High School in 2003,[11] she went to Ecuador, Peru, and Bolivia in South America for four months as part of the Traveling School, an open learning environment. She attended George Washington University for a year, and then transferred to New York University's Gallatin School of Individualized Study, where she studied psychology, international social policy, and nonprofits,[12][4] graduating in 2010.[13]
Mara was inspired to act by seeing musical theatre and classic movies, like Gone with the Wind (1939), Rebecca (1940), and Bringing Up Baby (1938), with her mother.[14] She also wanted to be like her sister, Kate Mara, a professional actress. Patricia resisted pursuing acting as a child, stating to The Journal News that "it never seemed that honorable to me, and I guess I was always afraid that I might fail."[2] Her first and only role in high school was Juliet in Romeo and Juliet, which she got after being signed up to audition by a friend.[15] Mara acted in a few student films while at NYU, and then began her career in acting,[2] first auditioning at the age of nineteen.[4]

source :http://en.wikipedia.org/wiki/Rooney_Mara