The Dark Knight Rises actress and partner Guilluame Canet welcomed a baby boy in May 2011, an event to which Cotillard is still adjusting.
"I've never been more exhausted. But I've never had more energy," Cotillard told Vogue of balancing work and motherhood. "This is the paradox of being happy. That's where it comes from."
The Dark Knight Rises director Christopher Nolan also revealed to the publication that he is such a fan of Cotillard's acting that he restructured much of the film's production schedule to fit around her due date during her pregnancy.
"The word challenging is thrown around as some kind of pejorative to mean an actor who's difficult. But Marion is challenging in the true sense of the word. She's so good you don't want to waste that talent. You want to hold up your end," he explained.
Cotillard plays Wayne Enterprises executive Miranda Tate in the latest instalment in the Batman franchise.
> 'The Dark Knight Rises' video clip released - Watch
Watch the trailer for The Dark Knight Rises below: