Ledger's family would accept the Oscar

"If Heath Ledger wins the Oscar for Best Supporting Actor on Feb. 22, his family will accept the award on his behalf, Dark Knight director Christopher Nolan told EW.com at the DGA Awards Saturday night. Nolan accepted Ledger's Golden Globe award on Jan. 8, and Ledger's Dark Knight costar Gary Oldman took the stage on behalf of the young actor at the SAG Awards on Jan. 25. Nolan did not elaborate on which members of Ledger's family would accept should Ledger win, but previous family statements have been made by Ledger's father, Kim, mother, Sally, and older sister Kate, and it's possible all three would step to the front of the Kodak on Oscar night".
Source: hollywoodinsider.ew.com