Nicole Richie says her entire life revolves around new baby Harlow , PEOPLE reports.

Nicole Richie says her entire life revolves around new baby Harlow

"Joel actually changes more diapers than I do," the new mom says of boyfriend Joel Madden, in an interview with Extra conducted during her Harper's Bazaar photo shoot (for the June cover). "It's his time with her. He sings to her. ... He laughs with her, plays with her. It's amazing."

"Everything I do is for her," Richie, 26, tells Extra. "I was so excited from the minute I found out I was pregnant ... and it's been nothing but an amazing ride since."