Pippa Middleton

(CBS) Apparently, not everyone is a fan of royalty.

Pippa Middleton, the younger sister of Kate, Duchess of Cambridge, heard this for herself while speaking with a group of children during an event to promote her new party-planning book, "Celebrate."

Middleton, 29, was doing a craft project with youngsters at the event when she told a 6-year-old tomboy, "I bet when you're 10, you'll love pink and you'll love princesses."

That caused another little girl to state, matter-of-factly: "I hate princesses."

Middleton laughed off the remark and said, "I don't know about that one."

Her book, "Celebrate: A Year of British Festivities for Families and Friends," was released in the U.K. on Oct. 25 and will arrive on U.S. bookshelves Tuesday.

© 2012 CBS Interactive Inc. All Rights Reserved.