Pippa Middleton, sister to the Duchess of Cambridge, formerly known as Kate Middleton, poses for the media as she arrives at a bookshop to promote her new book "Celebrate: A Year of British festivities for families and friends", in London Thursday, Oct. 25, 2012. (AP Photo/Kirsty Wigglesworth)

Pippa Middleton, sister to the Duchess of Cambridge, formerly known as Kate Middleton, poses for the media as she arrives at a bookshop to promote her new book "Celebrate: A Year of British festivities for families and friends", in London Thursday, Oct. 25, 2012. (AP Photo/Kirsty Wigglesworth)

LONDON, ENGLAND - DECEMBER 05: Pippa Middleton and James Middleton leave the King Edward VII Private Hospital on December 5, 2012 in London, England. Their sister Catherine, Duchess of Cambridge is spending a third day in the King Edward VII Hospital after the announement of her pregnancy and the fact she was suffering from hyperemesis gravidarum or acute morning sickness. (Photo by Dan Kitwood/Getty Images)

Besides her royal connections, Pippa Middleton is well steeped in party planning. She has professional party-planning experience with London-based Table Talk, and she comes from a family of party planning experts. (Photo by Chris Jackson/Getty Images)

LONDON, ENGLAND - JUNE 29: Pippa Middleton and then-boyfriend Alex Loudon attend a match at Wimbledon. (Photo by Julian Finney/Getty Images)

Pippa Middleton, sister of Catherine, Duchess of Cambridge, arrives for a semifinal between Spanish player Rafael Nadal and British player Andy Murray at at the Wimbledon Tennis Championships at the All England Tennis Club, in southwest London on July 1, 2011. AFP PHOTO / GLYN KIRK RESTRICTED TO EDITORIAL USE (Photo credit should read GLYN KIRK/AFP/Getty Images)

LONDON, ENGLAND - SEPTEMBER 19: Pippa Middleton is seen at the front row during the Temperley runway show at London Fashion Week Spring/Summer 2012 at the British Museum on September 19, 2011 in London, England. (Photo by Tim Whitby/Getty Images)