`The Dark Knight Rises` actress admitted that she has struggled to find a balance between work and motherhood, after giving birth to son Marcel last year (20.05.11).

She said: "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."

The star plays Wayne Enterprises executive Miranda Tate in the upcoming Christopher Nolan-directed movie.

He said he believed in the French actress - who also appeared in his 2010 motion picture `Inception` - so much that he restructured the film`s $250 million production schedule around her due date.

The 36-year-old Oscar winner`s one-year-old child is fathered by 39-year-old actor boyfriend, Guillaume Canet.

He told the August issue of American Vogue: "The word challenging is thrown around as some kind of pejorative to mean an actor who`s difficult.

The 41-year-old film professional added: "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."
sections: Celebrities