Kate's sister, 30, has penned her last column for the British publication, a source at the paper confirms to PEOPLE.
"She is a freelance writer, she wrote it for six months and she has gone on to other publications," the source says.
Her last dispatch ran on March 29, when she wrote about joining the Cambridge University boat crew for training, as well as their favorite recipes.
Pippa, whose 2012 book Celebrate championed all that is good about parties and British holidays, also wrote about how to flip the perfect pancake and the famous oyster restaurants in the seaside town of Whitstable, asking if the shellfish were "really an aphrodisiac?"
Her most recent article for Vanity Fair is a guide to Royal Ascot Week, which involves 30 horse races and $9 million in prize money.
Along with the horse parade and the hats, Pippa humorously discusses the different car parking lots, where racing fans eat their lunch.
"Apparently, Car Park 1 is the place to picnic and to be seen, although spaces in this car park are passed on like a dead man's shoes," she writes.