The youngster, who is the Duchess of Östergötland, happily accepted flowers from her waiting fans while simultaneously beaming at the flag-bearing crowd.
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Princess Estelle's first official handshake
Estelle, who is similar in age to Prince Christian of Denmark when he carried out his first engagement, walked hand-in-hand with her father as the royals arrived at the castle, before being scooped up into Daniel's arms for the last part of the walk.
George was aged just eight-months when he attended a playgroup at Government House in Wellington.
The Duke and Duchess of Cambridge's son began his royal duties much earlier than his European counterparts, with Princess Ingrid of Norway starting aged five and Princess Elisabeth of Belgium officially attending a church service when she was four.