Nicole Richie says she does everything for new baby Harlow — except change her diapers.

“Joel actually changes more diapers than I do,” the new mom, 26, said of beau Joel Madden, in an interview with Extra airing Thursday. “It’s his time with her. He sings to her …. He laughs with her, plays with her. It’s amazing.”

Otherwise, says Nicole, the tot is at the center of her life.

“Everything I do is for her,” she says. “I was so excited from the minute I found out I was pregnant … and it’s been nothing but an amazing ride since.”

Although the former ‘Simple Life’ star is the first in her circle of friends to have become a parent, “I feel like my group of five to 10 friends, they really love her, like she’s theirs … My friends never go outside for smoke breaks anymore, they don’t curse, they are definitely more demure. It’s actually been really interesting.”