Since Prince George's birth in July, the Duchess of Cambridge has rarely been seen in public as she adjusts to life as a mother.
In September, Prince William and Kate spent their first night away their son to attend a black-tie awards ceremony.
The Duchess had previously made her first surprise public appearance since George's birth when she joined her husband as he started the Anglesey Coastal Ultra Marathon in August.
More top news
Kids Company founder Camila Batmanghelidjh to leave the children's charity, blaming politicians 'ugly games' and austerity for her decision.
A prison officer - who was allegedly assaulted by a prisoner at a crown court - has died.
The body of the girl, who is thought to be about four, was found washed up in a bag in Boston.