The singer was already bonding with her future godchild, while spending time with her pregnant BFF Jaime King.
In a video, which Swift posted to Instagram with the caption: "Checking up on these two," Swift's hand can be seen on her friend's belly while the baby kicks.
"He's sticking his arm up for you," King can be heard saying.
"Oh my God. That's crazy!" the "Blank Space" singer is heard responding. "Happy Mother's Day."
The "Hart of Dixie" actress, 35, recently opened up to Elle magazine about why she chose the pop star as her second baby’s godmother.
"There was no thought behind it at all other than that I always knew she was going to be the godmother if I had another baby," King said. "It's because she's incredibly thoughtful. Choosing a godmother is a very sacred and important thing in our family."
The actress said she asked Swift while they were just hanging out on the couch. "I was like, ‘Hey, would ever want to be a godmother?’ And she was like, ‘Uh, yes!’ And she cried and, you know, all the fun things that best friends do," she said.
The best friends announced the news on social media in March with a cute Instagram pic of Swift touching King's belly.