Grief is not a simple emotion to articulate, but actress Billie Lourd tried to convey her emotions in a birthday post for her late mother Carrie Fisher, referring to the loss as a "weird soup of feelings."

On what would have been the "Star Wars" star's 69th birthday, Lourd shared a photo with her mother and late grandmother Debbie Reynolds, accompanied by a touching tribute on Thursday, Oct. 21.

"This is the 9th birthday of hers I've 'celebrated' without her," Lourd began her caption. "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."

"Every time I meet someone older than her I'm secretly jealous," she continued. "Why couldn't she have lived as long as they have? Anyone out there who has lost a loved one too young can maybe relate? So I can't really call it a wholly happy birthday cause she isn't here to enjoy the happy."

The 33-year-old Los Angeles native said she's saddened Reynolds did not have the chance to meet her grandchildren, including Lourd's 5-year-old son Kingston Fisher and 2-year-old daughter Jackson Joanne. Lourd called her kids, whom she shares with husband Austen Rydell, "magical, smart, hilarious, kind creatures."

On days like Oct. 21, Lourd finds herself simultaneously "sad" and "mad" about the loss of her mother. Her own multifaceted grief, Lourd says, can be best described as soup that's "not always the tastiest, but it might make you a stronger, healthier human."

"Grief is a weird soup of feelings and there are a lot of ingredients in it that are hard to swallow, but ultimately I think the soup has made me healthier - more cognizant of how short life is and more appreciative of all the happy in my life," she added.

Billie Lourd talks to children about late mom Carrie Fisher

Lourd said Kingston recently asked how Fisher died, and she responded, saying "she didn't take care of her body - telling him the truth without telling him the whole truth."

"Oh, but I take care of my body!" he replied.

"Yes you do! And I do too and daddy does too!" she told her son.

Lourd said she didn't need to go into details about how their grandmother died, adding, "Death isn't looming at our doorsteps the way it always was for her." However, she said the exchange broke her heart and made her more mad at Fisher.

"It's weird being mad at a dead person because you don't really have anywhere to put the emotion. 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," Lourd said. "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."

She wants her children to know Fisher as the "brilliant magical human" she was, so she continues to celebrate "the good parts" amid the complicated feelings.

"So despite the many emotions I have on these days I try to celebrate the good parts," she added. "I'll tell my kids funny stories about her, watch one of her movies, eat one of her favorite foods, have a Coke. Happy birthday momby. I miss you and love you more than you could ever know."

How did Carrie Fisher die?

Carrier Fisher died of cardiac arrest at age 60 on Dec. 27, 2016. The "Empire Strikes Back" actress suffered a medical emergency soon before her flight from London to Los Angeles was due to land on Dec. 23. Four days later, she died at Ronald Reagan UCLA Medical Center.

Fisher's mother and "Halloweentown" star Debbie Reynolds died on Dec. 28, 2016, shortly after her daughter's passing.

At age 84, Reynolds died after suffering a stroke in Beverly Hills, California, with TMZ reporting that she was planning her daughter's funeral.

Billie Lourd unpacks 'weird' feelings of grief on late mom Carrie Fisher's birthday