Desperate to help, Mrs Larder called on her London-based twin daughters, Nicola and Victoria, who have both worked in television and radio.
With their assistance - "how could they say no to their mother?" - she pulled together a committee comprising Jews and non-Jews, including former Board of Deputies president Henry Grunwald QC, and a number of other "well-connected people" in the arts and media. Longtime Groucho Club host Bernie Katz signed up straight away, bringing with him an enviable contact book from his years as gatekeeper to the stars.
Soon after, the committee met at Beth Shalom for a tour and a talk by a Holocaust survivor. The groundwork was laid and the White Rose ball - so named after the emblem of the anti-Hitler student resistance movement in Nazi Germany - was born.
Opened in 1995, Beth Shalom was founded by non-Jewish brothers Dr James and Dr Stephen Smith to raise awareness in Britain about the Nazi atrocities and other campaigns of genocide.
Mr Katz, who had not visited the centre before, said he had found it an amazing place. "It has such a great collection, but the Holocaust will be completely forgotten in a few generations unless we do something."
He said he considered his involvement in the ball "not a duty, but an honour.
"Whether you are Jewish or not, the Holocaust is something that can't be lost," he said. "It has to be acknowledged and we have to do all we can to keep the memory alive".
He added that he intended the night to be the first of many. "Next year I want the ballroom at the Savoy," he said.
With four months until the big day, details are still being finalised, but the committee have promised a night to remember. Mrs Larder said she had been astounded at the generosity of businesses, with many offering food and entertainment for free.
Actress Maureen Lipman is set to host, while a private dinner with shoe designer Jimmy Choo, a costly Fabergé egg and a dance lesson from West End lead Adam Garcia will be among the money-can't-buy prizes up for auction.
After a champagne reception, around 350 guests will be serenaded by Elaine Paige and treated to a meal with each course prepared by a different celebrity chef, including Tom Parker Bowles, Mark Hix and Fergus and Margo Henderson.
Alex James from the band Blur, now a noted cheesemaker, is designing the cheese course.
Stephen Fry, whose Hungarian grandparents fled to Britain to escape the Nazis, but lost relatives in the Holocaust, is helping develop the event.
He said he was "proud beyond measure" to be involved. "It will help us remember that we must never forget the atrocities of the Holocaust or let them be repeated, ever, ever, ever" .
Dr James Smith, co-founder of Beth Shalom, said he was deeply moved to see people taking it upon themselves to ensure the centre's work would continue.
"I can't wait for the ball. It will not only raise money but I hope also raise the profile of the centre - we'd love more visitors. "
For Mrs Larder, it was the natural thing to do. "The centre is a wonderful place and it has really touched my heart," she said. "I just wanted to help."
The White Rose Ball will be held on September 25 at the Kia Oval in the England Suite, which has been provided free of charge. Find out more here
White Rose Ball
