Duchess Catherine visited the St. Thomas' Hospital in London on Tuesday to officially launch a campaign to promote nursing worldwide.
During the event, Kate - who is expecting her third little prince or princess in April - chatted happily with nursing staff, families and patients in the Snow Leopard Ward at Evelina London Children's Hospital, which is part of St. Thomas.'
While experiencing first-hand the expertise and dedication of nurses as they care for children, the royal kept the conversation light-hearted by joking that Prince William was still "in denial" about the arrival of baby number three.
Jamie Parsons, the father of a 10-month-old receiving care at the hospital, told People he was wishing her luck when she made the funny comment. "I was saying, 'Congratulations, best of luck with the third one,'" Parsons said.
Her response to him: "William's in denial."
Kate, 36, kept her growing baby bump cozy in a custom-made Jenny Packham military-inspired coat with silver detail, worn over a matching blue dress for the engagement. She completed her look with Jimmy Choo high-heeled shoes and a blue clutch.
Earlier in the day, Kate visited the Royal College of Obstetricians and Gynaecologists (RCOG) to learn more about the facility's global health programs aimed to reduce maternal and newborn mortality worldwide.
While at the event, the beloved royal shared an emotional reunion with Professor Dunkley-Bent, who assisted with the delivery of Princess Charlotte, who was born in May 2015 at St. Mary's Hospital.
The duo appeared completely delighted to see one another as they hugged and exchanged a few brief words at the afternoon function.
In a statement, Prof Dunkley-Bent, head of maternity, children & young people at NHS England, said: "It was a surprise and an absolute pleasure to be reunited with Kate again today."
"Supporting families at the birth of their baby - including future kings and queens - is hugely rewarding and we're very grateful to have the Duchess of Cambridge's support for the nursing profession."
Kate was also announced as the new patron of RCOG - a position which was previously held by Queen Elizabeth the Queen Mother, who passed away at the age of 101 in 2002.
The mother of Prince George and Princess Charlotte may have already entered the third trimester of her pregnancy, but she's showing no signs of slowing down.
The Duchess and husband William are set to make their first official appearance alongside Prince Harry and Meghan Markle on Wednesday, February 28.
According to Kensington Palace, the couples will be participating in the inaugural Royal Foundation Forum and will even take the stage together.
"The Duke and Duchess of Cambridge, Prince Harry and Ms. Meghan Markle will take part in the first annual Royal Foundation Forum on Wednesday 28th February," the palace wrote in a statement published to Twitter.
"Under the theme 'Making a Difference Together,' the event will showcase the programmes run or initiated by The Royal Foundation, including @heads_together, @WeAreInvictus and @united4wildlife."
The statement concluded: "TRH and Ms. Markle will appear on stage together to discuss why The Royal Foundation was set up, the projects they are currently working on, and their ambitions for the future."
As the foundation was initially set up by Kate, Wills and Harry as the main vehicle for their philanthropic activities, it's an exciting step forward for Meghan -- a true welcome into the fold, if you will!