BUSINESS CLASS: Regulars at fashion weeks worldwide, the Clarins sisters are not just pretty faces. Spotted at the Valentino show, Prisca, daughter of Olivier Courtin, said she launched nail bar chain Nail Factory in France 18 months ago and now has three locations in Paris. “Parisian women were waiting for a concept like mine, because it did not exist here before,” she commented. Her ambition is to have 10 Parisian outlets within five years, and to open the concept to franchise outside the capital. Virginie, daughter of Groupe Clarins chairman Christian Courtin-Clarins, said she was also in the process of setting up her own firm, but was mum on details. The show also drew Jessica Biel, Ciara, Alexa Chung and Natalia Vodianova.