Jamie wrote in a heartfelt Instagram tribute that her older sister “was jaw-droppingly beautiful and a talented actress”

Kelly Lee Curtis — the sister of Jamie Lee Curtis and the eldest daughter of Tony Curtis and Janet Leigh — has died. She was 69.

Kelly died “at peace” at her California home on Saturday, May 30, according to Jamie, 67, who announced the death in a touching Instagram post. The cause of death has not been shared at this time.

“A warm aloha to my older sister, Kelly Lee Curtis. She passed away this morning. In her home. In nature. At peace,” the Oscar winner wrote alongside a black-and-white photo of her late sister.

Jamie added that Kelly was “my first friend and lifelong confidant.”

“She was jaw-droppingly beautiful and a talented actress,” she continued. “She played a mean game of hearts, collected turtles, loved her family, nature, music, thrifting, travel … She was proud of her Danish roots and Hungarian Jewish ancestry and was a devoted American patriot.”

BEVERLY HILLS, CA - NOVEMBER 20: Actress Jamie Lee Curtis (L) and Kelly Lee Curtis arrive at the Los Angeles Premiere "Hitchcock" at AMPAS Samuel Goldwyn Theater on November 20, 2012 in Beverly Hills, California. (Photo by Barry King/FilmMagic)

Kelly Lee Curtis in 2012.Barry King/FilmMagic/Getty Images

The Halloween star went on to say that her sister will be remembered “for her loving generosity, fierce opinions, endless curiosity, unique style, and her powdered, almond, crescent cookies at Christmas, hence her name, Auntie Cookie.”

“Kelly always signed off any message or fare thee well with a Hungarian blessing … Isten Veled, God is with you. Isten Veled to my sister of the sun and the moon, my Tai. I’ll see you on down the line,” Jamie concluded.

PEOPLE has reached out to Jamie’s representative for comment.

Tony Curtis, Benjamin Curtis, Kelly Curtis, Nicholas Curtis, Allegra Curtis and Jamie Lee Curtis attend Tony Curtis' Art Exhibition Dinner Party on April 22, 1989.

Tony Curtis, Benjamin Curtis, Kelly Curtis, Nicholas Curtis, Allegra Curtis and Jamie Lee Curtis in 1989.Ron Galella, Ltd./Ron Galella Collection/Getty

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Kelly was the eldest of late actors Tony and Leigh’s two daughters, followed by Jamie. Tony had four other children: daughters Alexandra, 61, and Allegra, 59, with second wife Christine Kaufmann and sons Nicholas, who died aged 23 in 1994, and Benjamin, 53, with third wife, Leslie Allen.

Kelly was born in Santa Monica, Calif., and appeared alongside her parents in her first uncredited role in the 1958 movie The Vikings. She later starred alongside her sister Jamie in Trading Places (1983), per The Hollywood Reporter. 

Kelly continued acting and appeared in several TV shows throughout the 1980s and 1990s, including The Equalizer, HunterSilk StalkingsStar Trek: Deep Space Nine and a recurring role on the first season of The Sentinel. She also worked as Jamie’s assistant on several of her films, per CBS News.

Kelly is survived by her husband, Scott Morfee.