POWER OF TWO: French contemporary brands are tapping a new wave of collaborators in the form of young and social “It” girls. Dreaming of warmer days, Olympia Le-Tan has designed a French Riviera-themed embroidered schoolgirl’s satchel and printed canvas tote bag for the summer collection of French contemporary clothing label Claudie Pierlot. Model and actress Dree Hemingway has created an Americana-inspired capsule collection for Sandro, which will bow in all the stores in March. The line includes dresses, embroidered T-shirts and skinny white jeans, in addition to accessories including a leather clutch. Sandro is organizing a launch party at its Bleecker Street store in New York on Feb. 7. Retail prices range from 85 euros, or $111 at current exchange, for a T-shirt to 245 euros, or $322, for a leather clutch. Meanwhile, socialite Eugenie Niarchos has developed a line of sweatshirts and T-shirts for summer in collaboration with luxury cashmere designer Lucien Pellat-Finet.