Kate Middleton's three day bachelorette party

Kate Middleton is having a three day bachelorette party.

The 29-year-old beauty - who will marry Britain's Prince William on April 29 - is having a party organised by her sister Pippa to celebrate her last days of being unwed, but won't have a traditional hen party because it is not "an option".

A source said: "Kate was desperate to have a hen do, but a boozy night out on the town was never really an option - plus, that's not really her style."

Instead, Kate, who met William while the pair both studied at St. Andrews University, will celebrate at either Balmoral Castle or Frogmore House.

The first day will involve pampering of the small number of guests, including socialites Rose Astor and Emilia d'Erlanger, with manicures and pedicures by staff from Kate's favourite London salon.

The second day will have a more extravagant feel with a party and DJ.

The source added to Britain's Grazia magazine: "The second night will start with a three-course dinner followed by dancing. Kate has apparently asked for her favourite DJ, Sam Young, and a karaoke machine.

"The next day will be more formal, with Kate's mother Carole and William's cousins Zara Phillips, along with Princesses Beatrice and Eugenie joining the hens for lunch."

It is still not known what designer will create the future princess' dress for the big day at Westminster Abbey, but she has been encouraged to pick an unknown to help them with their career.

British Fashion Council chairman Harold Tillman said: "I would respect Kate for giving an unknown a break - so long as it's a British designer, of course."