"Kate was talking to my daughter about clothes and how she was feeling too hot. She said: 'I really shouldn't have worn this,'" Karen told The Metro.
At the time Karen also gave Princess Charlotte a doll. Charlotte also received a pink inflatable flamingo from another royal fan and went over to say thank you.
Karen is well known for taking the ‘fab four’ photo of the Cambridges and Sussexes walking together in 2017 to church.
WATCH: Kate Middleton and Prince William talk about Princess Diana in their engagement interview
In 2019 Kate and William's youngest child, Prince Louis, did not join his parents at the church, however many other royals did join them including The late Queen, Prince Charles (who is now King Charles) and the Duchess of Cornwall.
The upcoming holiday season will mark the first Christmas since beloved Queen Elizabeth passed away.
But her son, King Charles will honour her memory by continuing her favourite Christmas tradition: spending the holiday at Sandringham, the much-loved country retreat of the royal family located in Norfolk.