updated 10/21/2009 AT 6:00 AM ET
•originally published 10/21/2009 AT 7:30 AM ET
Six weeks after welcoming their first son, Nicole Richie and Joel Madden – along with their 21-month-old daughter Harlow – are showing off the latest addition to their family, Sparrow James Midnight Madden.
“I couldn’t be happier,” Richie tells PEOPLE. “The only thing you want is for your kids to be healthy and happy, and they are. I’m right where I belong.”