The day would have marked the Hollywood icon's 85th birthday. Debbie died last December, days after her daughter and Billie's mother, Carrie Fisher, who was 60.
"Happy 85th to my constantly classily clad Abadaba," Billie wrote on Instagram, alongside a candid photo of her mom and grandmother inside a hotel room. Debbie is wearing an emerald green pants and matching duster and black top, while Carrie sports a multi-colored printed scarf over a black outfit.
Debbie's nickname comes from her Carleton Carpenter's hit cover of the song "Aba Daba Honeymoon" for their 1950 film Two Weeks With Love.
Debbie and Carrie were honored at a public celebration of their lives last Saturday. Many of their family members and friends, including celebs, attended the memorial, which had followed a private funeral. Even Star Wars droid R2-D2 made an appearance.
"My mother didn't like memorials or funerals," Carrie's brother Todd Fisher told the crowd. "She liked shows, parties...so this show was really time for you to be in our living room as if we were all a big family."