[1] In 1962, she raced in Lightnings to win the Syce Cup, the Long Island Sound Women's Championship now called the Queen's Cup, beating out the previous champion Timothea Larr.
[2][3] Sinclair sailed with her sister Alexandra Falconer and Carolyn McCurdy in Coral Gables, Florida to win the 1962 United States' Women's National Sailing Championship, the Mrs. Charles Francis Adams Trophy.
[4] Sinclair continued to win racers and in 1963 she won the Stamford Yacht Club regatta, sailing with her sister Alexandra Falconer and Katie Morgan.
[1] Sinclair earned the Martini and Rossi Trophy in 1962, now called the Rolex Award, for the United States Sailor of the Year.
[1] Sinclair was a teacher educated at the National Louis University in Illinois.