According to Debbie's son, she died of stroke, reports tmz.com.
Debbie was rushed to a hospital shortly after 1 PM when someone at the Beverly Hills home of her son, Todd, called 911 to report a possible stroke.
According to tmz.com, Debbie and Todd were making funeral plans for Carrie, who died Tuesday of cardiac arrest.
Debbie famously divorced Eddie Fisher in 1959 after his affair with Elizabeth Taylor. Debbie married two more times in 1960 and 1984.
She played iconic roles in "Tammy and the Bachelor" and "The Unsinkable Molly Brown" for which she earned an Oscar nomination.
Carrie's relationship with Debbie was the focus of Carrie's semi-autobiographical book, "Postcards from the Edge," which was later adapted for the big screen, starring Meryl Streep and Shirley MacLaine.
Debbie is survived by her son Todd, who tells us, "She's with Carrie."