Katherine Heigl expected adopting again would take "years".

The 34-year-old actress and her husband Josh Kelley adopted their first daughter, Naleigh, now four, from South Korea and wanted to take on the care of an overseas child again, but after finding the process incredibly slow and complicated, the couple decided to look into domestic adoption.

They were stunned when it took just a matter of weeks to welcome Adelaide, now eight months old, into their home.

Speaking on 'The Tonight Show with Jay Leno', she said: "This was fascinating because we started the adoption process again and we thought we were going to adopt internationally. It's a pretty long process. It can take years.

"And then we started exploring because we had heard that Korea had gotten very hard to adopt from, and China had a very, very long waiting list and I was like ... any day now.

"And so we started exploring the idea of domestic adoption - just exploring - and then my lawyer called and said, 'There's a birth mother and she's due in four weeks and she's all yours if you want her.' "

Singer Josh, 32, was particularly stunned by the speed of the process, but his wife thinks things worked out perfectly as they were both able to spend so much time with their new baby daughter.

She added: "He thought it was going to be a few years, and that we were going to end up with more of like a nine month old or 10 month old, and he looked at me and said, 'You're telling me in a month we're going to have a newborn?' And I said, 'Yes. It's perfect timing, don't you think? Look we're both here, we're not working. This is great. We can spend time with her.' And it has been beautifully serendipitous and graceful, because we've gotten to spend all this wonderful time with her."