Grayson was born as Betty Evans on October 9, 1925, in Portland, Oregon.[1][2] Grayson was educated at Franklin High School, Portland, graduating in 1944.[3][4]
Grayson began playing softball aged 13.[2] She initially played for the Lind and Pomeroy Florists’ softball team in the Portland City League as an outfielder, then trained as a pitcher under her father's coaching.[5] Grayson pitched in her first of six ASA nationals championships in 1943.[5][6][7]
In 1944, Grayson won the ASA National Title in the Women's Major Fastpitch Tournament in Cleveland, Ohio with the Lind and Pomeroy Florists’ softball team.[1][8] She "dominated" the mound with four no-hitters.[8] For her performance, the Oregon Sportswriters and Broadcasters Association named her “Woman Athlete of the Year.”[8] She was nicknamed "Bullet Betty."[7]
After playing for the Lind and Pomeroy Florists’ softball team for seventeen years, Grayson signed to play for the Chicago Queens for three years.[9] By the end of her career, Grayson had a 456-99 won-loss record with 51 no-hitters and three perfect games.[5][8]
Grayson was inducted into the ASA National Softball Hall of Fame in 1959.[5] She was inducted into the Oregon Sports Hall of Fame as a member of the Lind & Pomeroy Florists in 1982.[4] She was inducted into the Portland Interscholastic League Hall of Fame in 1985.[3]
Grayson worked outside of her softball career as a clerk in the city of Portland's license bureau.[10]
Grayson died of breast cancer in 1979, aged 53.[2][5][8]