Fay Sinkin was born on March 24, 1918 in New York. She earned a bachelors degree from Syracuse University. Sinkin was devoted to community activism; she was elected President of the San Antonio League of Women Voters in 1947, organized the Visiting Nurse Association in the 1950s, and was the first woman to serve on the San Antonio Board of Health. She was named the Express/News Woman of the Year in 1953.
In the 1970s Sinkin led the efforts to protect the Edwards Aquifer, organizing the Aquifer Protection Association. In 1983 she was the first woman elected to the board of directors of the Edwards Underground Water District. In 1989 she formed the Edwards Aquifer Preservation Trust, which worked to protect the recharge zone from over-development. She was inducted into the San Antonio Women's Hall of Fame in 1985, and was listed in the Who's Who of American Women.
Sinkin married banker and community activist William R. "Bill" Sinkin in 1942, and had two sons, Richard and Lanny. She passed away in 2009.