Bertrand died Saturday afternoon at Cedars-Sinai Medical Center after a 7 1/2-year battle with cancer, Jolie said in a statement released by her manager. No age was provided.
Jolie, Brad Pitt and her older brother, James Haven, were at the hospital Saturday, the statement said.
Bertrand, who had small roles in the movies "Lookin' to Get Out" in 1982 and "The Man Who Loved Women" in 1983, raised Jolie and her brother after divorcing their father, Oscar-winning actor Jon Voight, when Jolie was a toddler.
A private funeral was planned.
In lieu of flowers, the family asks donations be made to the Women's Cancer Research Institute at Cedars-Sinai Medical Center.