Princess Charlotte was heard saying her first words in public as her and brother George attended children's party during the royal visit to Canada.
The youngest royal couldn't contain her excitement when she saw balloons and eagerly ran over to them yelling: "Pop!"
The 16-month-old was later overheard saying "da da" to her father Prince William as he gave her a cuddle.
Not wanting to be left out, Prince George, now three, ran over when he spotted a balloon animal being made for his little sister.
"But I want one, can I have one?" he was heard saying to his mother Kate.
In touching family scenes, William showed his son how to blow bubbles.
While Charlotte played with a rattle-type toy and later playfully sat on a dog and was delighted by a black and white rabbit.
George enjoyed a ride on a miniature pony and ran around squirting his father and sister with an orange bubble gun during the party in Victoria, British Columbia.
The garden of the official home of Judith Guichon, Lieutenant Governor of British Columbia, had been transformed into a children's paradise for George and Charlotte and a group of children from military families.
Children's entertainer Paul Kilshaw made George and Charlotte balloon animals and received unusual requests from the prince - a spider and a volcano.
He added: "When I made him the spider he started to laugh and pushed it in my face then pushed it in dad's face.
"William said 'we try making balloons at home but it doesn't work'".
George wore his usual clothes combo of shorts, shirt, jumper and knee length socks while Charlotte wore a blue dress and a cardigan.
Most of their week-long visit to Canada has been carried out in private without the glare of the media.
On Tuesday, the children went to Beacon Hill Children’s Farm in Victoria where they reportedly petted some goats.
Local media said the children have also visited Willows Beach, which is one of Victoria's most popular swimming beaches.