Kate Winslet hosted the Cardboard Citizens gala fundraiser in London on Saturday. The actress arrived in a white dress by French designer Max Chaoul, before auctioning it off later that evening to help raise funds for the charity. She's been a longtime supporter of the nonprofit, which helps homeless people get back on their feet through theater. Kate, whose new ads for Lancôme were just unveiled, has had a busy March full of philanthropy, modeling, and press duties. Her can't miss HBO miniseries, Mildred Pierce, debuts on the 27th, and she also graces the current cover of Glamour. Kate is already getting awards buzz for her new role, but told the magazine one of her biggest achievements is keeping her kids grounded and polite despite her fame.