And that moment came this week, when the Grey's Anatomy beauty released pictures of her adorable ten-month-old daughter on her fundraising website.
Alongside the intimate shots of the new family unit – who are currently adjusting to their lives together - the site explains that Naleigh is a nickname for Nancy Leigh.
The name is a combination of the monikers of Katherine's mother Nancy and her sister Margaret Leigh, who was also adopted from Korea.
In an recent interview with Ellen DeGeneres, the 30-year-old star revealed that she narrowly missed out on sharing a birthday with her new daughter, who has special needs.
"She was actually born the day before me in November which I thought was really serendipitous and just kind of like a sign," she told the chat show host.
"I realised just recently that I basically forfeited my birthday for the rest of my life."