Her slinky and sensual dresses made Daniella Helayel famous among the in-crowd. Then the Brazilian-born designer moved even higher up the fashion ladder after Catherine Middleton chose one of her designs for her engagement dress.

Yesterday, the designer celebrated the 10th anniversary of her Issa collection at London Fashion Week. "I've been through my archives. This is an explosion of print," she said.

The designer's autumn/winter 2011/12 designs demonstrated the slinky, sensual silhouette she has become famous for. Pheasant, feather, shell and animal patterns were printed on flirty dresses and soft, silky jersey gowns, while draped "goddess" gowns came in vibrant jewel tones of cobalt, amber and scarlet.

She celebrated the "ages of woman" with a sensational finale featuring Yasmin Le Bon – whose husband, Simon, and 16-year-old daughter, Tallulah, were in the front row – and Andrea Dellal, the former "Brazilian bombshell of the catwalk".

Other front-row guests included the models Cara and Poppy Delevigne, Rod Stewart's daughter, Ruby, and Tamara Beckwith's daughter, Anouska.

Samantha Cameron, who officially opened London Fashion Week, has been hailed by Harold Tillman, the chairman of the British Fashion Council, as a "brilliant ambassador".

The Prime Minister's wife has now officially joined the First Ladies of America and France in the world's most famous Style Trio.

On Friday evening, when Mrs Cameron hosted an event to mark the opening of London Fashion Week at No 10, she showed her flair for fashion in a feminine, over-the-knee skirt, printed with stars, from the feisty, young Glaswegian designer, Christopher Kane.

On Sunday night she will stage a second reception at Downing Street, this time for US buyers and journalists, co-hosted by Anna Wintour, the editor of American Vogue.

Mrs Cameron has a self-confessed love of fashion and the creative arts, as well as an insider's knowledge as the creative adviser for the Smythson luxury goods and stationary company.