At first glance, her life could be plucked from a Nancy Mitford novel. She is a viscountess. Her first husband, Sir Reginald Sheffield, is a baronet. Her second husband William Astor, fourth viscount Astor, is also the nephew of her mother’s second husband Michael Astor, son of the American-born Nancy Astor, of the legendary parries with Winston Churchill. Her grandfather, Sir Roderick Jones, was head of Reuters. And her daughter Samantha is married to David Cameron, the British prime minister.

Yet at 62, Lady Annabel Astor has trumped inherited titles and carved out an independent identity with a title of her own: chief executive of OKA, a furniture and interior design company that she founded with friends Sue Jones and Lucinda Waterhouse. Lady Astor herself prefers to avoid all titles: “It’s Annabel,” she says.

Her stylish house in Belgravia, London is testament to the artistic ability of her family. The apple-green walls of the ground floor are plastered with gold-framed prints and watercolours that share space with inherited Astor art, including a painting of a horse called “Pay-Up”.