"Tonight we are choosing to celebrate and be happy for what he has achieved," said his mother Sally Bell, who stood alongside Heath's father, Kim Ledger, and sister, Kate, on the stage of Hollywood's Kodak Theatre.
Added Kate, in reference to Heath's 3-year-old daughter, who will inherit his Oscar when she turns 18, "We proudly accept this award on behalf of your beautiful Matilda."
Asked backstage whether Heath's daughter knows about all the Oscar hoopla, Kim told reporters that Matilda's mom, actress Michelle Williams, "keeps Matilda closeted, in a nice way, and [Matilda] won't know very much about the fuss that's going on."
Ledger's mother said that Matilda's resemblance to her late father is striking. "You just have to look at her to know that she is totally like her daddy," said Bell. "She has the same mannerisms. I really feel he's in her."
Ledger was the favorite for the Oscar after having won multiple awards earlier in the season, including the Critics Choice, the Golden Globe and the Screen Actors Guild award.
Ledger, 28, was found dead in a New York apartment on Jan. 22, 2008, of an accidental overdose of prescription drugs.
Family Arrived Last WeekThe actor's family arrived in Los Angeles last week in hopes that Ledger's work would be honored on Hollywood's biggest night. Williams did not attend the ceremony but was in Los Angeles on Saturday for the Film Independent's 2009 Spirit Awards. Williams was a best actress nominee for the film Wendy and Lucy at the Spirits.
On Feb. 19, the Ledgers attended the Australians in Film Academy Award Celebration where Oliver Ackland of Sydney became the inaugural recipient of a scholarship created in Ledger's name.
"The family caught up with lots of Heath's friends [at the event]," said a guest. "It was a bittersweet night but celebratory, as well.
Reporting by SARA HAMMEL