Helen Sandy Pflueger Phillips (born 1954) is an American equestrienne. She has competed successfully in both eventing and dressage, finishing second at the prestigious Badminton Horse Trials in 1981 and competing on the United States Dressage Team at the 1984 Los Angeles Olympics.On 1 February 1997, Sandy Pflueger married British Olympian and coach of the American Eventing team, Captain Mark Phillips, whose first wife was Princess Anne, the daughter of Queen Elizabeth II. Mrs.