The Oscar-nominated actress watched a parade of glamorous gowns and outfits designed by American fashion label OneStopPlus.com, catering for Women above a US size 12.
Organiser Nancy Le Winter commented fashion was not just for the skinny and anyone should be able to wear stylish designs.
She said: "It's simply about time that fashion speaks to all women. It is the first time that women can look around and say, 'I can wear that!' "
Former winner of 'America's Next Top Model' Whitney Thompson also declared plus-sized women should still be able to walk on a runway.
She said: "There is no reason a size 16 model should not hold their head up high like everyone else."