Prince George and Princess Charlotte held their dad's hand as they walked in.
Savannah silencing Prince George on the balcony mirrors an earlier moment with Prince Harry and Princess Beatrice.
She wrote it in a letter of support for 'remarkable' children’s hospices.
And Prince Louis has hand-me-downs from his big sister, too.
About Duchess of Cambridge
Born on January 9 1982, the Duchess of Cambridge is five months older than Prince William. The pair married on 29 April 2011, having met at Scotland's University of St Andrews in 2001. The couple split briefly in 2007, but later reunited and became engaged during a holiday in Kenya to celebrate the Prince passing his RAF helicopter search and rescue course. On 14 January 2013, St James's Palace announced that the Duchess was expecting her first child in July 2013.