Billie Lourd has admitted grief can be a "weird soup of feelings" in a candid message to mark her mother Carrie Fisher's birthday.

The Star Wars actress died at the age of 60 in December 2016 after suffering a heart issue on a flight. Carrie's mother, Hollywood icon Debbie Reynolds, passed away the following day at the age of 84.

Taking to Instagram on Tuesday, Billie celebrated what would have been Carrie's 69th birthday by posting a throwback photo of the Postcards from the Edge writer and Singin' in the Rain star posing together.

"My mom would've been 69 years old today. Which still feels shockingly young because this is the 9th birthday of hers I've 'celebrated' without her," she began. "It feels like she has been dead so long that she should be 100 at this point? It feels more okay for a 100-year-old person to be dead? But not a 69-year-old."

Billie went on to note that she's sad Carrie never got to meet her grandchildren, Kingston, five, and Jackson, two.

In addition, Billie recounted how her little boy recently asked how Carrie died.

"I told him that she didn't take care of her body - telling him the truth without telling him the whole truth," the 33-year-old explained. "Death isn't looming at our doorsteps the way it always was for her. That's a conversation for later years."

Elsewhere in the lengthy post, Billie admitted she sometimes feels "mad" at Carrie for not getting sober after years of struggles with drug addiction.

"It's weird being mad at a dead person because you don't really have anywhere to put the emotion," she continued. "But it's still there and I've had to learn to allow myself to feel all the things - mad at her for not getting sober but also sad for her that she wasn't able to get sober but also happy that she existed at all. So I allowed myself to be mad for a moment but then realized I also do want her birthday to have some happy in it."

And to conclude her emotional message, Billie shared that she will celebrate the "good parts" by watching some of Carrie's favourite movies and eating some of her go-to foods.

"Sending my love to anyone out there having to eat the multifaceted soup that is grief. It's not always the tastiest but it might make you a stronger healthier human? Happy birthday momby. I miss you and love you more than you could ever know," the Ticket to Paradise star added.

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