Marguerite Littman was beside the pool at the Hotel Cipriani in Venice with Tennessee Williams when a cadaverous girl came shambling past wearing a bikini. “Look, anorexia nervosa,” Littman said to her companion. “Oh, Marguerite, you know everyone,” came Williams’s reply.

It was true: David Hockney, Bianca Jagger and Bill Blass were among Littman’s associates. Truman Capote was said to have modelled his Southern heroine Holly Golightly in Breakfast at Tiffany’s on her, Elizabeth Taylor sought to emulate her drawl when playing Maggie in the film adaptation of Williams’s Cat on a Hot Tin Roof (1958), and she shared with Princess Diana a running list of people who brought “oxygen into a room”.

Andy Warhol recalled visiting her in London in 1978 to meet Rock Hudson over lunch, but the actor’s flight was delayed. “Marguerite invented something great for dessert — chocolate soup,” he noted in his diaries. “It’s orange juice and Grand Marnier and chocolate, hot.” She was a neighbor of Margaret Thatcher and a friend of Koo Stark.

Petite, vivacious and funny, Littman was not only a “zigzag” socialite, as she described her energetic rise through society, she was also the moving force behind the Aids Crisis Trust at a time when Aids was considered to be the curse of drug users and those with outré sexual proclivities. She nursed Hudson as he was dying from the condition in 1985 and two years later summoned a lunch party of four friends to discuss doing something. They told her she would need trustees, an accountant, a solicitor — and a lot of effort. Within a week everything was in place, including Diana’s involvement and Cardinal Basil Hume’s encouragement.

Elizabeth Taylor sought to emulate Littman’s drawl when playing Maggie in the film adaptation of Cat on a Hot Tin Roof.

Littman, whose life, she said, revolved around “collecting people”, wrote to 300 acquaintances asking for $132 each. “Only one turned us down. We had no overheads, as we licked our own stamps and used our own telephone. The accountants wouldn’t believe there were no administration costs, so they made us put in a claim for $7.” She persuaded friends to provide works of art for a Christie’s sale that raised $329,000; Hockney’s contribution was his Alphabet, a collaboration with Stephen Spender. Even donors paid the entry charge. “I made a strict rule there were to be no freebies, no favorites,” she added in a voice that was once described as suitable for marinating a ham in.

In 1996 Diana set in motion what became known as the most-celebrated rag sale in history. “She rang me in the morning,” Littman recalled. “She said, ‘I have a wonderful idea. I’m going to give you all of my dresses.’ I didn’t know quite what that meant. I thought, Oh, God, do I dress that badly?” The result was the sale of the princess’s outfits in New York in 1997, two months before her death. It raised $5.7 million for Aids and cancer work.

She shared with Princess Diana a running list of people who brought “oxygen into a room.”

Marguerite Lamkin was born in Monroe, Louisiana, in 1930, the daughter of Ebb Lamkin, a lawyer, and his wife, Eugenia (née Speed); her brother Speed Lamkin, who died in 2011, was a novelist and playwright described by the composer Ned Rorem as “the poor man’s Truman Capote”. The Lamkins had great agricultural wealth, owning one of the big plantations in the area, while their children were extroverts with a flair for the theatrical: they put on a show every Saturday with Speed as the maestro and Marguerite the star, often wrapped in a lace cloth.

At 18 she went to Finch, an elite finishing school in New York, before reading philosophy at Tulane University, New Orleans. While there she visited her brother, by then a student at University of California, Los Angeles, and met his exciting friends. Staying on the west coast, she found work as a telephonist in the House of Paper store but had to leave because the phone lines were jammed with callers wanting to hear “House of Paper” in her Southern twang.

The Hollywood producer Jerry Wald said that she looked like a young Susan Hayward and promised to get her into the movies if she lost her accent. She practiced speaking with stones in her mouth, but to no avail. Instead she resolved to “teach people to speak the way I do”. She worked on a dozen films, including Baby Doll (1956), Raintree County (1957) and The Long Hot Summer (1958), helping Elizabeth Taylor, Paul Newman, Margaret Leighton and others to “speak Southern”. Her closest friends in Los Angeles were Christopher Isherwood and his partner, Don Bachardy. “We were playmates,” she said of Bachardy, who lived in her apartment.

Seen here in London with Jerry Hall, Littman once said her life revolved around “collecting people.”

Littman was comfortable among gay men, with Spender describing her as “an ally … against the gossiping classes of Hollywood”. Nevertheless, she had countless suitors including a man with dwarfism who pushed notes under her door, hid in bushes to watch her pass and left gifts of Le Creuset cooking pots in her hallway. The poet Edward James, who introduced her to the composer Igor Stravinsky, proposed in a 50-page love letter, but she never got past the second page.

After six months in Hollywood she married Harry Brown, the screenwriter who won an Oscar for his screenplay of A Place in the Sun (1951), but he grew jealous of her popularity. “When I said I was going to leave him, he said he would shoot me,” she told The Mail on Sunday. “So I called Christopher [Isherwood] to say goodbye, but his line was busy. I told Harry I was going out to buy some lamb chops, and never went back.”

Crossing the country, she started a new life in New York and met Warhol, but claimed to have declined his offers of countless paintings. “I don’t believe in taking pictures from young artists,” she said. “They need to sell. He did give me one soup can. I lent it to somebody and it disappeared.”

She published some short stories, edited a collection of photographs by Richard Avedon and became arts editor for Glamour magazine. Her advice columns for lovelorn young women, written under the pen name Daisy, included a list of “teddy bear tricks” that any resourceful “young lady” should be prepared to use to make a man “feel he’s your King Giant”. Number three, designed to keep him interested, was: “Don’t put his flowers in a vase; leave them in the sink.”

She had countless suitors including a man with dwarfism who pushed notes under her door, hid in bushes to watch her pass and left gifts of Le Creuset cooking pots in her hallway.

Her second marriage was in 1959 to the actor Rory Harrity; on their wedding night he was appearing in Noël Coward’s farce Look After Lulu! on Broadway while she went to the opening of a Tennessee Williams play. Harrity was a dipsomaniac and after a “Dear Daisy” column appeared under the heading “Help a drinker?” (answer: “Drinkers must help themselves”), they were divorced.

Beneath the Southern charm was a feeling of unease about her family’s history. On one occasion she accompanied Avedon to her childhood stomping grounds in Louisiana to document segregation for a book called Nothing Personal (1964) that he was photographing for the novelist James Baldwin. “I didn’t tell anyone in New Orleans what we were doing because I didn’t think they would approve,” she admitted to The New York Times.

Littman once described her husband’s job as: “You know, the ones who wear ‘weegs.’”

In 1963 she met Mark Littman, a British QC, while he was visiting Manhattan. They were married two years later in Nassau. “I couldn’t use any teddy bear tricks, because he knew I was Daisy, but something worked,” she recalled. They settled in London, where he became head of chambers at 12 Gray’s Inn Square. She once memorably described his position as: “You know, the ones who wear ‘weegs’.”

Home was a townhouse in Chester Square, Belgravia, central London, where Littman, at times a little eccentrically, entertained in the Deep South style that she had known in Louisiana. One visitor recalled a house “stuffed with beautiful things, fragrances and colors”. Hockney’s glorious painting of Isherwood and Bachardy hung in the dining room, itself dominated by a chandelier made from antlers with a large convex mirror on the wall.

Genuine Louisiana food was served at her lunch parties, which were invariably fundraisers disguised as theatrical events. Once she wrapped all the huge potted plants in cloths, each looking like a turban, while on another occasion she gave a lunch for 30 men and one other woman, the actress Brooke Hayward. Her husband died in June 2015 and thereafter she was cared for by Victor, their house manager; she had no children.

The Aids Crisis Trust was dissolved in 1999 because, Littman said, it had achieved its primary goal of getting the British establishment involved and was duplicating the efforts of the Elton John Aids Foundation, of which she became a director. “I like Elton,” she drawled. “He’s funny.”

A friend who met Littman in the 1980s described her as having a “magical quality”. He added: “Part of it is her Southern accent and part of it is her fey mannerism. It’s removed but engaged at the same time. You might even say it’s what Holly Golightly would have been if she had grown up.”

Marguerite Littman, socialite and charity fundraiser, was born on May 4, 1930. She died on October 16, 2020, aged 90