Lisa de Kooning, Artist and Patron Who Preserved Father’s Legacy, Dies at 56

De Kooning. (Courtesy Patrick McMullan)

Johanna Liesbeth de Kooning, the philanthropist and sculptor who helped to guide her father Willem de Kooning’s art career in the last years of his life and to preserve his legacy after his death in 1997 at the age of 92, died at her home on St. John in the U.S. Virgin Islands on Friday, according to a statement from the Johanna Liesbeth de Kooning Trust. She was 56. As of press time, the cause of her death had not been determined.

The only daughter of de Kooning and illustrator Joan Ward, Ms. de Kooning, who went by Lisa, was granted legal control over her father’s business matters in 1989, when he was suffering from Alzheimer’s disease, a responsibility she shared with John Eastman, the son of Willem de Kooning’s longtime lawyer Lee Eastman. Their efforts contributed to the critically lauded retrospective at the Museum of Modern Art last year, the artist’s first major museum exhibition since his death.

John Elderfield, the curator of the MoMA show, told Gallerist that the exhibition “couldn’t have been done without her support,” because the artist’s estate retained so many unique records and other documentation, which Ms. de Kooning opened to him and his team. Mr. Elderfield said that he offered to sign a confidentiality agreement—such archival materials can be sensitive—but that, trusting him implicitly, she told him that was not necessary. “She said, ‘I absolutely wouldn’t dream of having you sign anything,’” he recalled.

“She was very ebullient and very kind to people,” Mr. Elderfield added. “She was really, really proud of [her father], but she was also her own person.”

“For decades, curators, dealers and collectors have been continually surprised by her keen insights and her subtle understanding of the history and the essential nature of de Kooning’s art,” Marc Glimcher, the president of the Pace Gallery, which began representing Ms. de Kooning’s collection of her father’s works in 2010, said in a statement. “I will always remember those moments and all the laughter and joy that was Lisa.”

Ms. de Kooning was born in New York City and lived in Springs, N.Y., not far from her father’s East Hampton studio, which she worked to preserve. However, dealer Larry Gagosian, who represented Ms. de Kooning’s collection from 2003 to 2010, told Gallerist, “She wasn’t as much of an art-world person as you might expect, being the daughter of such a great artist,” noting her involvement in a wide variety of charities and nonprofits.

Among the groups Ms. de Kooning supported were art institutions like the East Hampton sculpture garden LongHouse Reserve, the Noguchi Museum in Long Island City and the Watermill Center, in Water Mill, N.Y. (in a statement, its artistic director, Robert Wilson, wrote, “She was an angel.”), but also the Boys and Girls Harbor, the Springs Fire Department and the East Hampton Day Care Learning Center.

She was a dependable presence on the gala and party scene in the city and the Hamptons.

In a statement, the de Kooning Foundation, which Ms. de Kooning and Mr. Silberman started in 2001 to conserve and promote the artist’s legacy, wrote, “[She] will be remembered not only for her commitments to the arts and her local communities, but for her spontaneous expressions of good will and kindness toward those she encountered in daily life.”

She also loved animals, focusing much of her time on their rights, and kept a number of them at her homes. “She had three or four dogs, pigs, a pile of rabbits and miniature horses,” Mr. Elderfield recalled, describing her home near her father’s storied workspace in East Hampton. “One of the little horses figured out how to trot into the kitchen of the studio and open the fridge.”

Animals were the focus of much of the art made by Ms. de Kooning, who studied at Bernard Pfriem’s Lacoste School of the Arts in the south of France. She worked primarily in sculpture.

“She was so talented,” said Priscilla Morgan, an arts patron and lifetime trustee at the Noguchi Museum who knew her for some 40 years. She was particularly fond of one of Ms. de Kooning’s cow sculptures, which she keeps in her home. “Everybody goes into the room, and they come out saying, ‘Wow, that work of Bill’s!’ And it’s really Lisa’s!” she said. She added, “She was the most generous, kind, darling, witty person, full of laughter.”

Mr. Gagosian recalled that, when planning shows of de Kooning’s work, Ms. de Kooning would often offer advice. “She had a very good sense of what the strongest paintings were,” he said. “She’d obviously spent a lot of time looking at her father’s work. She had a very good eye for it.” He also credited her with maintaining her father’s studio and allowing collectors, scholars and young artists to visit it just as it was when her father died.

Her charity work extended to St. John, where she had a home. She supported the Virgin Islands National Park, among other causes. According to a report late last week in the Islands’ St. Croix Source newspaper, a gentleman who was at the residence early on Friday morning reported to police that he heard a loud crash and found Ms. de Kooning on the floor outside of her bedroom. Because the cause of death is uncertain, the territory’s police department is investigating, its PR rep said on Tuesday afternoon.

In recent years, Ms. de Kooning had started a residency program in East Hampton, allowing young artists to work in the studio where she once watched her father paint.

She is survived by her three daughters, Isabel, Emma and Lucy de Kooning Villeneuve.

Lisa de Kooning, Artist and Patron Who Preserved Father’s Legacy, Dies at 56