From childhood, Susan's interests revolved around horses and she was a keen show jumper and avid polo player that provided a connection to the British royal family. On January 17, 1956, she married Major Ronald Ivor Ferguson (1931 - 2003), who would later become the Queen's polo manager. The couple had two daughters: Jane Louisa, born on August 26, 1957, and Sarah Margaret, later the Duchess of York, born on October 15, 1959.
Divorced, she married a second time in 1975 to professional polo player and widower, Hector Barrantes of Argentina. She moved to Argentina where she and her husband maintained a large ranch at El Pucara, breeding polo ponies and cattle. In 1990 her second husband died of cancer.
Shortly before the automobile accident that took her life, Mrs. Barrantes authored a book titled "POLO" with the foreword written by the Prince of Wales.
She is buried in La Recoleta Cemetery in Buenos Aires, the capital of Argentina.