In 1937 , her filly Mars Shield won the Kentucky Oaks then on May 4 , 1940 Ethel Mars had her greatest single achievement in racing with her colt Gallahadion .
In 1937 , her filly Mars Shield won the Kentucky Oaks . 
 Then on May 4 , 1940 , Ethel Mars had her greatest single achievement in racing with her colt Gallahadion .