As the middle sister growing up in a family of three girls and as the former designer of Bonpoint and creator of Bonton, Domitille Brion knows a thing or two about dressing teenage girls. Last spring she teamed up with her sister Angélique Brion to create Soeur, a Paris boutique specializing in cool clothing for girls ages 10 to 14 and their little sisters. The clothes and accessories are also proving popular among petite Parisian moms (88, rue Bonaparte, 75006 Paris; 33-1-46-34-19-33).