- Lady Louise Windsor, 7, William's first cousin on his father's side. She is the daughter of his uncle, Prince Edward and Sophie, Countess of Wessex.
- The Hon. Margarita Armstrong-Jones, 8, William's second cousin. The daughter of Viscount and Viscountess Linley first came into the public spotlight in 2006, when William swung the delighted 4-year-old into the air as they were walking to church for Christmas Day service.
- Eliza Lopes, 3, granddaughter of Prince Charles' wife Camilla, the Duchess of Cornwall. Eliza's mother, Laura, is Camilla's only daughter from her previous marriage to Andrew Parker Bowles. When Laura Lopes got married in 2006, her stepbrother, Prince William, and Kate Middleton attended the wedding.
- Grace van Cutsem, 3, godchild of Prince William. The royal family and the van Cutsems are reputedly very close and Prince William often stayed with the van Cutsems as a child.