Her mom, Carrie Fisher, and grandma Debbie Reynolds died days apart in 2016.
The "American Horror Story" actor posted a clip on Instagram of her singing "American Girl," one of Fisher's favorite songs.
Director J.J. Abrams had originally written her character out of Fisher's scenes in "Star Wars: The Rise of Skywalker."
The 26-year-old actress sang a song to her mother, who died in 2016 at the age of 60.
"This one goes out to anyone having a less than perfect Mother's Day today."
The late actress won best spoken word album for her memoir "The Princess Diarist."
Fisher died in December 2016 after suffering a heart attack.
Who's cutting onions?
"Happy birthday mom, I sure do miss you and the cozy days."