Nicole and Sparrow Richie on the cover of People Magazine

Nicole Richie and boyfriend Joel Madden introduced their 6-week-old son Sparrow James Midnight to People this week. "I couldn't be happier," Richie says.

Nicole Richie, Joel Madden welcome a son

"The only thing you want is for your kids to be healthy and happy, and they are," she tells the magazine. "I'm right where I belong."

Richie, 28, and Madden, 30, are also parents to a 21-month-old daughter, Harlow, who has adjusted to her big sister role with ease. "She's very gentle with him," Madden says.

Check out photos of Richie throughout the years

"I'm glad I had a girl before I had a boy," Richie adds. "She just loves him so much."