CELEBRATING PRINCESS KATE'S RETURN TROOPING THE COLOUR THE ROYAL FAMILY JOYFULLY REUNITE FOR KING CHARLES'S SPECTACULAR BIRTHDAY PARADE

It was the heartwarming public family reunion the world had been waiting for.

- EMILY NASH

As the Princess of Wales stepped out onto the balcony of Buckingham Palace, surrounded by her loved ones, the crowds thronging The Mall below cheered wildly in response.

Standing next to the King and Queen, her husband, Prince William, and their children-Prince George, 10, Princess Charlotte, 9, and six-year-old Prince Louis - Kate waved back joyfully, seemingly thrilled to be back alongside her family.

Making her first official appearance in public since Christmas Day as she continues to undergo treatment for cancer, the princess looked quietly delighted to be taking part in the traditional moment following the King's Birthday Parade.

She seemed especially touched to be watching the military flypast once again with her adored children, leaning in to chat with them about the spectacle.

Prince Louis turned excitedly to say something to his mom as the first Chinooks flew toward the palace.

While her sons gave double-handed waves to the crowds surrounding the Victoria Memorial, Kate tenderly adjusted her daughter's hair.

And in a sign of how strongly they've supported each other in recent months, William and Kate exchanged loving glances, clearly happy and relieved to be back together in public as a family unit.

Hello! understands that Kate discussed her decision to appear at the ceremony with her father-in-law, the King, beforehand, with a spokesman confirming, "His Majesty is delighted that the princess is able to attend."