[12][11] She attended Bronxville High School and excelled in field hockey (she was goalie) and basketball (center), graduating in 1974,[12] and she also competed in tennis and track.

"[1] She worked as a financial analyst at the Wall Street brokerage firm of P. R. Herzig and Company for ten years.

"[11] In 1984, she made it into the Guinness Sports Record Book with a 289-pound (131 kg) clean and jerk, an Olympic event featuring a two-stage lift of a barbell above one's head.

[12] In 1984, she was recognized as the world record holder for women's weightlifting in the 82.5 kg category, based on her results from a competition in Florida.

[7] In 1987, the first year in which there was a world championship for women in weightlifting,[17] Marshall competed for the United States against a surprisingly strong team from China.

[11] The Guinness Sports Record Book credited her as being the "world's most powerful female" because of her lifting 303 pounds (137 kg) overhead.

[24] A snatch is the other Olympic event in which a barbell is raised from a platform to locked arms overhead in a smooth continuous movement, pulled as high as possible, typically to mid chest height.

[13] In 1991, in a send-off of the United States team to the Olympics, Marshall set "Festival records for the snatch (198 1/4), clean and jerk (264 1/2) and total (462 3/4) at 181 3/4 pounds.

[27] Marshall began studying to be a chiropractor at Northeast College of Health Sciences based on her successful experiences as a patient.

[26] She attributed much of her success in weightlifting to chiropractic because it steered her away from painkillers and towards drug-free and non-surgical forms of treatment and prevention, she said in an interview.

[26] She explained her decision to become a chiropractor allowed her to "stay involved in health and fitness, while at the same time being able to use my knowledge and experience to help other people.