Socialite Amanda Hearst attended the Hamptons fundraising gala for Best Buddies at the Water Mill estate of her mother, Anne Hearst McInerney. Publisher William Randolph Hearst’s great-granddaughter arrived on the arm of her new boyfriend, Alejandro Santo Domingo, son of Colombian business magnate Julio Mario Santo Domingo.

This week, Amanda begins work as the associate market editor of the U.S. edition of Marie Claire, the fashion magazine owned by her family’s Hearst Corporation, where she will report directly to M.C. fashion director Nina Garcia. She previously held editorial positions at Harper’s Bazaar, Town & Country, and Spanish Cosmopolitan. She visited Wyntoon, the Hearst clan’s California compound, with close friend Ashley Bush earlier this summer.

Harvard-educated financier Alejandro, uncle of Tatiana Santo Domingo and brother-in-law of Vogue’s Lauren Santo Domingo, was most recently linked with Karen Larrain and was once engaged to Eugenia Silva. Amanda ended her long-term relationship with Winston Lapham last year.

Her mother hosted a fundraising initiative for Best Buddies in Water Mill the previous summer as well. Anne is a childhood friend of the Shriver and Kennedy families, founders of the disabilities organization. She also sits on the board of Robert F. Kennedy Jr.’s Riverkeeper environmental group, alongside her daughter.

Photograph: Adriel Reboh/PatrickMcMullan.com.