By Lisa Ingrassia
October 05, 2009 12:00 PM

On Sept. 16, her first day in Atlanta filming the romantic comedy Life as We Know It, an exhausted and flustered Katherine Heigl whirled onto the set 45 minutes late with an entourage, a mouthful of apologies—and a really good excuse. One week earlier the Grey’s Anatomy star announced on The Ellen DeGeneres Show that she and her husband, musician Josh Kelley, were adopting a baby girl from South Korea—on very short notice. “She was in an absolute panic initially,” says Grey‘s costar Chandra Wilson. But when the couple met 10-month-old Naleigh on Sept. 10, “everything calmed down,” says Wilson. “You couldn’t see someone more in love with her baby.”

After all, being an adoptive mom was something that Heigl dreamed of for years. “It was something she felt strongly about,” says Grey‘s creator Shonda Rhimes. Which is why friends and family were overjoyed by Naleigh’s arrival. “I’m so excited for my brother and Katie,” Charles Kelley told PEOPLE. “He’ll have her on the golf course with a club in hand and a guitar before she can walk!”

The actress, 30, who met her husband while starring in his 2005 music video for “Only You,” didn’t wait to tell Kelley, now 29, of her hopes to adopt. Heigl was raised with her sister Margaret Leigh, 34, who was adopted from Korea (she also has a brother Holt, 41; her brother Jason died at 15 in a 1986 car accident). “[Adoption is] really important to me,” she told DeGeneres. “I wanted to make sure I was marrying a guy … who understood that that was going to have to happen.”

He did—and soon after their December 2007 wedding, they began applying to adopt, filling out an exhaustively detailed 40-page application. Says Heigl: “We were looking at these questions going, ‘We better answer these right!'” But there was no reason to worry. “They have a strong marriage,” says a friend. “They’re going to bring that to their family as it grows.”

Six months ago they learned they would become parents of a baby girl—and were expecting a long wait—when suddenly, officials said the adoption was going through. “She’s a special needs baby,” Heigl told DeGeneres (see box). “They wanted to get her to us as quickly as possible.”

Heigl and Kelley have been adapting to parenting Naleigh (named Nancy Leigh after Heigl’s mom, Nancy, and sister) on the fly. After introducing her to pals T.R. Knight and Ellen Pompeo, the actress whisked her from L.A. to Atlanta to film Life. Set sources say Heigl, who dubbed herself “the Diaper Queen” because of her mastery of the quick change, dotes on her daughter. While cradling Naleigh, says production assistant Katherine Avery, “she was nuzzling Katherine’s neck. It was very motherly and tender.”

That same vision had Kelley cooing as he bragged about his daughter (“She’s awesome!”) and debuted a song for her at his Oxford, Ohio, concert on Sept. 18. “Just to see you in your mama’s arms is all I need,” he sang, “to bring me to my knees.” No wonder that pals say Naleigh is in good and loving hands. “They are so funny and easygoing and they’ll share those qualities with this child,” says one friend. “They are going to love big.”