Wearing a green coat, hat and shamrock brooch, Kate Middleton and her husband chatted to parade participants, including Regimental Sergeant Major Ray Collister, who snuck in a cheeky question about children.
Collister asked Prince William if he and his wife were planning any "baby Micks," a nickname for members of the Irish Guards.
"Maybe one day. One's enough at the moment," William reportedly replied.
"He said maybe when there's time," Collister added.
William and Kate will be busy preparing for their tour of Australia and New Zealand, which kicks off next month in Wellington. Palace officials have confirmed that Prince George will travel with the family, and is expected to make a few public appearances.