TWIN STANDARDS: Possibly the youngest buyers in Paris, 15-year-old twin sisters Haya and Sama Abukhadra peered out beneath matching cascades of curls at the Colette Dinnigan show Saturday. The siblings were scouting for their mum, Rula Abu Khadra, who runs The Art of Living fashion store in Riyadh, Saudi Arabia. “We help when she doesn’t have the time to come to the shows,” said Haya, explaining that if a collection wins their seal of approval, mum then goes to visit the showroom. And do they have exactly the same taste? “Yes,” they chorused, adding Hussein Chalayan was their favorite.