Riley Keough and the twins.

The Daisy Jones and The Six actress, 35, gave fans a rare look at her twin sisters Finley and Harper Lockwood—whose parents are the late Lisa Marie Presley and Michael Lockwood—as she celebrated their 16th birthday on social media.

"Happy Sweet 16 to my angel girls," she captioned the Oct. 7 Instagram carousel post. "You are the most special girls in the whole wide world."

She gushed, "I am so lucky to be your big sissy."

Riley included a handful of sweet old photos of her with her younger sisters, showing off their closeknit bond. In one particularly notable snap, Riley, Finley and Harper are all smiles as they cuddle on the couch with their late mother. 

In another photo, which appears to be a more recent one, Riley is seen wearing a white bikini with jean shorts as she takes a mirror selfie with her teenage sisters.

The sisters' milestone birthday comes less than two years after their mother died at the age of 54 in Jan. 2023 due to a small bowel obstruction following bariatric surgery.

Following her death, Finley and Harper's guitarist dad, 63—who was married to Elvis Presley and Priscilla Presley's only daughter for 10 years before getting divorced in 2016—became their legal guardian.

Lisa Marie shared Riley and Benjamin Keough with her ex-husband, Danny Keough, who she was married to for six years until they divorced in 1994. Benjamin died by suicide in July 2020 at the age of 27.

Riley attributes her mother's profound heartbreak over Benjamin's tragic death as one of the reasons she died several years later.

"My mom tried her best to find strength for me and my younger sisters after Ben died, but we knew how much pain she was in," she told People in September. "My mom physically died from the after effects of her surgery, but we all knew she died of a broken heart."

The Under The Bridge actress is also bringing her mother's true story to the masses through a new memoir From Here to the Great Unknown, the majority of which will be comprised of Lisa Marie's own words, with Riley adding additional context.

"Few people had the opportunity to know who my mom really was, other than being Elvis's daughter," Riley said in January of the book, set to be released Oct. 8. “I was lucky to have had that opportunity and working on preparing her autobiography for publication has been a privilege, albeit a bittersweet one."

Keep reading for more moments between Lisa Marie and her kids.

Lisa Marie Presley posed with her daughters—Riley Keough and twins Harper and Finley Lockwood—and son Benjamin Keough in this June 2019 photo. The singer wrote on Instagram, "Mama Lion with cubs."

Lisa Marie was joined by her daughters and mom Priscilla Presley at a handprint ceremony at the TCL Chinese Theatre in Los Angeles on June 21, 2022.

Shortly after celebrating her 53rd birthday in February 2021, the singer posted a family photo with her girls alongside the caption: "Thank you for all of the overwhelming birthday wishes from everyone. Like everyday, I couldn't have made it through without these three by my side."

In 2013, the musician rang in Easter with her kids and mom.

Lisa Marie took Riley and Benjamin to the Hollywood premiere of Lilo and Stitch on June 16, 2002. The trio were accompanied by Lisa Marie's half-brother Navarone Garibaldi, who Priscilla shares with ex Marco Garibaldi.

The To Whom It May Concern artist was fêted by Finley and Harper on her 51st birthday in 2019. "Grateful to be happy, healthy and alive," Lisa Marie captioned a mother-daughter snap from the celebration. "And grateful for all of you."

Lisa Marie was accompanied by her daughters at Elle's 24th annual Women in Hollywood celebration on October 16, 2017.

"Love of my life," Lisa Marie captioned a selfie with Benjamin on Oct. 14, 2015. "One of the contents of my heart."

Amid the COVID-19 pandemic, Lisa Marie shared that she and her twins were fostering puppies from a local shelter. "Exhausting but so rewarding," she wrote on March 23, 2020. "Be well.

While celebrating Benjamin's 21st birthday on Oct. 21, 2013, Lisa Marie snapped this mother-daughter selfie. She tweeted, "love it when were all together."

"Incredible night at the Nutcracker ballet w my fave people in the world," Lisa Marie wrote in a December 2018 Instagram post. "Now it feels like Xmas."

Lisa Marie shared a sweet moment with her twins backstage at a tribute concert for Elvis Presley on Aug. 17, 2012. 

Lisa Marie and Riley unveiled a new Presley family exhibit at Graceland in August 2018. The "Lights Out" artist wrote on Instagram at the time, "Hope you all enjoy this little insight to my life."

The singer got matching tattoos with Benjamin as a Mother's Day gift.

In July 2022, two years after her son's death, Lisa Marie explained the meaning behind design. "It's a Celtic eternity knot. Symbolizing that we will be connected eternally," she wrote on Instagram. "We carefully picked it to represent our eternal love and our eternal bond."

Lisa Marie and her kids toasted with tea during a 2019 luncheon at the Plaza Hotel in New York City.

The family got together for an Easter Sunday celebration in 2015.

Lisa Marie supported Riley's movie The Runaways at a Hollywood premiere party on March 11, 2010.

Lisa Marie and Benjamin enjoyed a night out at the London premiere of Harry Potter And The Deathly Hallows: Part 1 on November 11, 2010.

In October 2018, Riley snapped a mirror selfie with her family at a backstage green room. Lisa Marie captioned the shot: "glamming it up with my loves for a special event!!!" 

Riley and Lisa Marie walk the red carpet at a launch party for Commando: The Autobiography of Johnny Ramone on April 27, 2012 in West Hollywood, Calif.

Lisa Marie was accompanied by her mom and her two oldest kids at a ceremony commemorating what would've been dad Elvis' 75th birthday in 2010.

Lisa Marie and Benjamin were snapped hanging out with DJ Ashba in December 2012, with the matriarch calling it a "fun night."

"Had such a lovely Birthday this evening with my Family [and] Friends!" Lisa Marie tweeted in February 2018. "Thank You everyone for all the LOVE and Birthday wishes!!"