The 36-year-old, who gave birth to son Marcel last year, said she has struggled to find a balance between work and motherhood, reported Contactmusic.
"I've never been more exhausted. But I've never had more energy. This is the paradox of being happy. That's where it comes from," she said.
The actress plays Wayne Enterprises executive Miranda Tate in the upcoming Christopher Nolan-directed movie.
Nolan believed in the French actress, who also appeared in his 2010 motion picture "Inception", so much that he restructured the film's USD 250 million production schedule around her due date.
