The Four Wedding And A Funeral beauty's 16-year-old daughter Sarah Margaret Qualley strutted her stuff for the first time at the celebrated designer's Philosophy di Alberta Ferretti show.
Qualley is following in her famous parents' footsteps - MacDowell modelled before becoming an actress and her father is former male model Paul Qualley.
The brunette looked every inch the catwalk queen as she wore a series of floral gowns in front of a star-studded crowd including Emma Roberts, socialite Amanda Hearst and Patricia Clarkson.
Details about dress designs for the bride-to-be have been a closely-guarded secret ever since the couple announced its engagement last year (10), but, on the eve of the big day, it has emerged the Brit has been selected to create gowns for the bridal party.
Middleton's sister Pippa will lead four other bridesmaids down the aisle at Westminster Abbey in custom-made Macfarlane outfits.
However, the bride-to-be has continued to keep fashion watchers guessing about whose creation she will wear when she exchanges vows with Prince William.
British designer Sophie Cranston's fashion house Libelula dismissed speculation the company had been commissioned to create Middleton's wedding dress, while Bruce Oldfield and Sarah Buxton, the creative director of late fashion king Alexander McQueen's label, have also been linked to the royal gown, which was designed and created at Buckingham Palace under royal watch.
Meanwhile, Alberta Ferretti has designed a dress for Prince Harry's girlfriend Chelsea Davy and Armani fashion chiefs have created a gown for Lady Frederick Windsor.
The British actress has already explored the world of fashion, fronting a campaign for style giant Burberry and designing an ethical clothing range for People Tree, and she is also working with Alberta Ferretti on a new organic collection.
But Watson is adamant she won't be expanding into perfume production.
She tells People.com, "I can't understand this fragrance thing. Why would you want to smell like somebody else? Don't you want to smell like yourself?... I will continue to work in the fashion industry."
Watson has modelled for British style giant Burberry and last year (09) became a creative consultant for Fair Trade fashion brand People Tree.
The 20-year-old actress has now confirmed she is working on a new project with Ferretti, revealing the Italian style guru approached with an idea for an organic collection after seeing her range for People Tree.
Watson tells Us Weekly, "We are doing an organic clothing range. I can't reveal the name yet but there will be more information about it soon... (Ferretti) wrote to me and said, 'I saw what you did with People Tree and I think it's a great idea and will you do something with me?'"
And Watson hints she won't be getting paid for her work with Ferretti, adding, "I will put it out there that I will work for anyone for free if they are prepared to make their clothing fair trade organic."
The collection is expected to be released next year (11).