Before Pippa Middleton marries former race car driver James Matthews on May 20, her big sis, the Duchess of Cambridge, Kate Middleton, is pulling out all the stops for a bachelorette party, Life & Style has learned.

“Kate is arranging a no-expenses-spared weekend at a luxury resort in the Swiss Alps for Pippa and 15 of her closest friends,” a source reveals of the girls’ trip.

MORE: Prince Harry is Miserable Without Fiancée Meghan Markle!

The activities list includes skiing, snowmobiling, ice-skating and massages. Plus, the source notes, “Kate is hiring private chefs to cook a lavish 10-course tasting dinner featuring some of Pippa’s own dishes.”

pippa middleton getty images

Pippa with fiancé James Matthews.

However, Kate is still working out the details on the weekend’s real showstopper: “She’s arranging surprise performances by the likes of Ellie Goulding,” the source explains, “and possibly some even bigger stars.”

MORE: For More Life & Style Exclusives, Sign Up For Our Newsletter!

For more on Pippa’s bachelorette weekend, pick up the latest issue of Life & Style, on newsstands now!

l&s cover