While visiting Oxford Children's Hospital, the royal spoke with mum-of-two Amy Scullard, whose 3-year-old son Emmet is in remission after being diagnosed with testicular cancer at just two.
According to HELLO! magazine, the pair immediately struck up a conversation about the Duke of Sussex's baby boy.
"Harry asked me if she was over the stormy period as babies are supposed to be grumpy for the first ten weeks," Amy told the publication.
"He said he's getting used to the baby and how Archie has fitted into family life. He said he just feels part of the family and he can't imagine life without his son."
During the emotional visit, Prince Harry was gifted with a teddy bear for baby Archie and was also reunited with 13-year-old Mikayla, a WellChild award winner who previously met the royal at the WellChild Awards in 2016.