Duchess of Cambridge
The Prince and Princess of Wales also said they're "delighted" to be back in the states for the first time since 2014.
The Prince and Princess of Wales are heading to the US this week for the first time since 2014.
The Princess of Wales also wore a dress from one of her favourite, go-to designers.
Kate Middleton's pearl necklace turned heads.
The Prince of Wales and Duke of Sussex walked in the processional for their grandmother on Monday.
Prince William and Kate Middleton's two eldest children will play a special role in their great-grandmother's funeral.
The Prince of Wales also walked behind his mother Princess Diana's coffin when he was just 15.
The royal brothers and their partners viewed floral tributes together outside Windsor Castle.
Charles III also mentioned his second son, Prince Harry, and his wife Meghan.
The seven-year-old had a busy day out with Kate Middleton and Prince William.
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.