Belgian actress Marie Gillain, who co-stars with Audrey Tautou in &ldquo;Coco Before Chanel,&rdquo; first became known as a teenager, when she played opposite Gerard Depardieu in &ldquo;My Father, the Hero.&rdquo;</p><p> She has had a successful career ever since, headlining films by top directors, including Bertrand Tavernier (&ldquo;Fresh Bait&rdquo;), Cedric Klapisch (&ldquo;Not For or Against&rdquo;) and Danis Tanovic (&ldquo;L&rsquo;Enfer&rdquo;).</p><p>As a young girl, Gillain had an irresistible buoyancy and self-confidence. This quality has given way in recent years to reveal something deeper, a watchfulness and a vulnerability underlying the surface gaiety. This has revealed a woman with a lot more doubt, gentleness and complexity than people ever realized &mdash; precisely the qualities that director Anne Fontaine needed for the role of Adrienne Chanel, Coco Chanel&rsquo;s older sister.</p><p>Last month, Fontaine and Tautou were in the United States for the publicity tour for &ldquo;Coco Before Chanel&rdquo; (which opened in Kansas City Friday). But Gillain, 34, had to stay home &mdash; she was eight months pregnant. We caught up with her at her local cafe in Paris&rsquo; fourth arrondissement.</p><p><strong> Q. Your performances have taken on a new vulnerability in recent years. How do you account for that?</strong></p><p><strong>A.</strong> When you&rsquo;re young, you have a certain purity, plus the idea that the world is yours. It&rsquo;s a big inspiration for directors. They use it, even sometimes in a dark way.</p><p> In the beginning of my career, the conflict between purity and something darker was in the movies I did. Afterward, of course, I grew, and when you grow, there are all the doubts coming in. For a long time, directors saw me as a young girl, very pure, quite fresh, and I had to give a new proposal of myself. Between 25 and 30, it&rsquo;s a passage.</p><p><strong>What drew you to Adrienne Chanel?</strong></p><p>What I like is that she&rsquo;s very representative of the women of her time. She has dreams, she is very romantic, but at the same time she has fear of not finding her place, the fear of being abandoned. What I really love about her is that she&rsquo;s never bitter, because it&rsquo;s quite rare, when you have a sister who has such an amazing career. But she&rsquo;ll always be loving her, and that&rsquo;s what I liked.</p><p><strong>Anne Fontaine says she was happy you took the role, because you&rsquo;re usually the star in your movies.</strong></p><p> It&rsquo;s different when you know you have 45 days to express a role. When you don&rsquo;t have a lot of scenes to express yourself, you really need to focus and try to be as generous and sensitive as possible, and sincere. For me the little sentence I had in my mind when I worked on this part was that Adrienne, in a way, is kind of the angel of Coco. She&rsquo;s the light part of Coco.