Kirk began racing motorcycles at the age of nine and progressed through the ranks of American Motorcyclist Association flat track competition during her teenage years. She reached the AMA Grand National Championship, the pinnacle of flat track racing in the United States, and in 1983 earned a spot in the Knoxville Half Mile event final — the first woman in history to qualify for a Grand National Championship final.
In 1986 she achieved another milestone, winning a Class C flat track race in Knoxville, Tennessee. Despite her results, Kirk encountered persistent obstacles: sponsors and parts suppliers refused to support a female competitor. Frustrated by the structural barriers, she retired from motorcycle competition and transitioned to stock car racing in 1989.
Kirk entered the NASCAR Winston All-American Challenge Series in 1991, becoming the first female driver to compete in the series. She steadily built her reputation on the touring circuit. In 1994 she was named the Most Popular Driver in the series, by then renamed the Slim Jim All Pro Series, and finished seventh in series points in 1996.
Her 1994 Snowball Derby victory made her the second woman to win a NASCAR touring series event — the first since Shawna Robinson's 1988 win in the Goody's Dash Series.
In 1997, Kirk made the step up to the NASCAR Craftsman Truck Series, signing with Geoff Bodine Racing. Her No. 7 Ford F-150 carried Loveable, a lingerie company, as sponsor in a deal reported to be worth $1.2 million. She debuted at the Walt Disney World Speedway, qualifying ninth and finishing 24th, becoming the first woman to compete in the series.
She showed pace early in the season: two races later at Portland Speedway she qualified third. Her best finish of 1997 was 11th at Heartland Park Topeka. After the Federated Auto Parts 250 she was released from Geoff Bodine Racing but completed additional races with MacDonald Motorsports and Circle Bar Racing. The Circle Bar entry ended prematurely when Kirk became uncomfortable in the improvised seating setup, citing instability in the turns. She ran 19 of 26 races that season and finished seventh in the Rookie of the Year standings.
For 1998, Kirk formed her own team running the No. 51 Ford. A lack of sponsors restricted her to 13 starts, and six of those ended as DNFs. Her best result of the year was 13th at Bristol Motor Speedway. Unable to attract sponsorship, she dissolved the team before the 1999 season and did not return to the Truck Series. Her career-best Truck Series finish remained the 11th-place result at Heartland Park Topeka in 1997.
Kirk returned to NASCAR competition in 2003, joining Jay Robinson Racing in the Busch Series driving the No. 49 Advil Ford Taurus. In 15 races her best finish was 21st at the Trim Spa Dream Body 250. She was released at the end of the season and has not competed in NASCAR since.
Kirk's dual career as a pioneering female competitor in both AMA motorcycle flat track and NASCAR truck racing established her as a barrier-breaking figure across two branches of American motorsport. Her 1983 Grand National Championship final appearance in Knoxville and her 1997 Craftsman Truck Series debut both represented firsts for women in their respective series. After retiring from competition, Kirk returned to Dalton, Georgia, where she works as a motorcycle dealer.