The Golden Globe-winning actress expressed her condolences on Wednesday, saying in a statement to People, "Although I only met her briefly, I wish her and her loved ones as much peace as possible."
Jessica Barrymore's body was found early Tuesday by a woman who was trying to leave for work when she found a car blocking her driveway, 10News reported. The car was in in National City, which is between San Diego and Chula Vista.
The woman told 10News that she'd found Jessica Barrymore reclined in the driver's seat, with a drink between her legs and white pills scattered on the passenger seat. A neighbor said the car had been parked there since around midnight.
As of Wednesday a cause of death had not been determined, the medical examiner's office told the San Diego Union-Tribune. An autopsy will be conducted in the next few days.
Drew, 39, and Jessica, who worked at a Petco store and would have been 48 on Thursday, have the same father, the late actor John Drew Barrymore. Jessica's mother is former actress Nina Wayne.
Drew told Marie Claire in January that she and her own mother, Jaid Barrymore, "can't really be in each other's lives at this point." Jaid was John's third wife.