Sandra was born in Boston, Massachusetts and trained with June Paxman from Washington Ballet and then with Boston Ballet, where she began performing at an early age. Her training continued with a Ford Foundation Scholarship at the School of American Ballet, where she made her mark with leading roles in SAB workshops and danced in Balanchine's Tarantella at the age of fifteen.
Invited to join Balanchine's New York City Ballet in 1974, Sandra spent nine years there, dancing an impressive repertoire of ballets not only by Balanchine but also by Jerome Robbins, John Taras, Jacques d'Amboise, Sir Frederick Ashton, Peter Martins and Auguste Bournonville. She has toured widely across the USA, also appearing on TV in the Dance in America series and Live from Lincoln Center.
Since 1985, as a freelance repetiteur for The George Balanchine Trust, Sandra has staged over 30 ballets for companies worldwide, including Apollo, Serenade, Concerto Barocco, Agon, Four Temperaments, Jewels, The Nutcracker, Midsummer Night's Dream and Donizetii Variations, as well as full-length classics (Giselle, Cinderella, Swan Lake, and Sleeping Beauty). She has taught for Royal Danish Ballet and was Ballet Mistress for Pennsylvania Ballet (1993-2002) and San Francisco Ballet (2002-2006) and has recently staged in Hong Kong and Santiago, Chile.