Kate Middleton's Sister Planning Top-Secret Bachelorette Parties
03/14/2011 AT 01:30 PM EDT
Pippa, 27, who's in charge of planning the "hen party" for Kate, 29, is actually preparing two celebrations – one somewhere in London and one at the Middleton family home in Bucklebury, Berkshire, reports Britain's Daily Mail.
Pippa has reportedly booked four venues in London and is keeping even the attendees in the dark about which is the real one. "None of the girls know where they will be going – and won't until the actual day," a source tells the paper.
Meanwhile, the soirée in Bucklebury, which Kate and Pippa's mother Carole will attend, is expected to have a Dirty Dancing theme.
Pippa, who is Kate's only sister, will be her maid of honor at Kate's April 29 wedding to Prince William. It's still unclear whether Pippa will be Kate's lady-in-waiting after the nuptials.