Pippa Middleton was spotted catching a tennis game on day nine of the U.S. Open 2012 in Flushing Meadows, NY.

Middleton attended the event with a group of girlfriends to catch the women's singles quarterfinals on Tuesday, Sept. 4. Daily Mail ran photos of the 28-year-old at the venue sitting next to tennis player Spencer Vegosen. He is seen smiling in images of him sitting next to Middleton, the sister of Kate Middleton, Duchess of Cambridge.

Pippa impressed the crowd with her formfitting color-blocked dress paired with wedge sandals.

The British socialite arrived to New York on Sunday, Aug. 2, courtesy of hotel magnate Andres Balazs. Balazs, who is worth a reported $450 million, flew her in on one of his private planes that landed at Sunset Beach in Shelter Island. However, her pass to the U.S. Open stated that she was a "Player Guest" to Roger Federer.

Pippa will release a book about entertaining and party planning in the United States next month.

The book, "Celebrate: A year of Festivities for Families and Friends," shares her insider knowledge on party planning. The Middleton sisters' family business, Party Pieces, offers expertise on event planning.

People released the first images of the book's front and back cover recently. The inside cover features Middleton's concept for the book as the following:

"This book is designed to be a comprehensive guide to home entertaining, based on my experience in my family's party business, Party Pieces , and work for London-based events company, Table Talk . It is a useful and practical journey into British-themed occasions and I hope it offers welcome inspiration and ideas, most of which needn't leave you alarmingly out of pocket. Entertaining on any scale can be stressful and daunting so this is all about finding ways to manage and enjoy the process.

I hope you will see this as a feel-good book with ideas to look forward to each month, providing threads of lasting, happy memories, be it around a table lit with candles in winter, outside on a rug in summer or in the autumn, perched on a leaf-covered bench, hot drink in hand."

"Celebrate" will be released by the Viking book publishing company and will be arrive in stores on Oct. 30 for $50.