Prince Williams and Kate, who are already parents to a year-old baby named George, announced on September 8 that they are set to welcome their second child.
Goulding, 27, who is a friend of Prince Williams' brother Harry and also performed at the wedding reception of Williams and Kate in 2011, said she is sure the couple will be great parents, reported Us magazine.
"I sent my congratulations already because I'm friends with Harry. I just think its beautiful. They're an incredible couple and I'm sure they're incredible parents. I'm just very happy for them.