The funeral forLee Radziwill— former princess, interior designer and younger sister toJacqueline Kennedy Onassis— will be held Monday morning in New York City’s Church of St. Thomas More, PEOPLE confirms.

The Catholic service is invitation only, according to church secretary Margaret Peet. A sourcetold Page Sixit’s “not a memorial. They won’t be doing anything else as she was so private and elegant.”

According to Page Six, among the likely attendees will be director Sofia Coppola, designer Marc Jacobs, Radziwill’s ex-boyfriend photographer Peter Beard and Radziwill’s surviving child, daughter Tina.

St. Thomas More is the same church where the memorial mass was held for Radziwill’s nephew John F. Kennedy Jr. and his wife, Carolyn Bessette Kennedy,according to theNew York Times.

Lee Radziwill in 1967.Reg Burkett/Express/Getty Images

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On Feb. 15, almost 20 years after their tragic deaths, Radziwill passed away in her N.Y.C.at the age of 85.

“She was warm but strong-willed, both formidable and playful,”Carole Radziwillrecently wrote of her mother-in-lawin a tribute to PEOPLE. “She still had a razor-sharp wit and intellect.”

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Carole, the widow of Radziwill’s son, Anthony, continued: “[Lee] didn’t set trends, she defined style. She expected authenticity and lived unapologetically. She was never in the shadow of anything. She was the sun.”

Beloved for her fashion sense, the former royal both inspired and competed with her older sister.

Married three times — and outliving all of her husbands — Radziwill had two children, Anthony and Tina.

Harry Benson/Express/Getty Images

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In her later years, Radziwill gave a few interviews about her legendary life. In 2013, she told theNew York Times: “Regrets? I think everyone has regrets, and people who say they haven’t are either liars… or narcissists.”

She continued then: “There have been many things in my life to have regrets about, in the sense I wish I could have changed them, or somehow made them not happen. What I don’t have is envy. I’m perfectly content at this time of my life. I’ve done so many fascinating things and the greatest joy is that I continue to do interesting things and meet fascinating people.”

Later in the same interview, she added, “When I was young, I used to think that everyone should die at 70… but my closest friends, like Rudolf [Nureyev] and Andy [Warhol] and, to an extent, [Truman] Capote, let alone most of my close family… didn’t even reach that age. There is something to be said for being older, and memories.”

source: people.com