Kinch was born in Ipswich, Suffolk, England and was a member of the Borough of Hounslow Athletics Club. She competed at the 1982 Commonwealth Games in Brisbane, winning the bronze medal in the long jump with a jump of 6.78 m.
In 1983, aged 19, she came 5th in the long jump final at the World Championships in Helsinki with a wind-assisted 6.93 metres. In the same competition, she set a British record of 6.90 metres, which stood until 2012. In 1983 she also won the gold in the 100 metres at the Universiade in a time of 11.13 (wind-assisted). The US magazine Track & Field News ranked her the seventh best long jumper in the world in 1983.
In 1984, Kinch competed in the European Indoor Championships in Gothenburg, where she won a gold medal in the 60 m sprint in a time of 7.16 seconds. Kinch was an outstanding talent, who seemed to have a brilliant future ahead of her, She earned selection for the 1984 Olympics at both 100 metres and long jump but was forced to withdraw because of injury and was never able to regain her former glory.
Kinch competed at the 1988 Olympic Games in Seoul as a member of the UK 4 x 100 metres relay quartet that reached the semi-finals. In 1990, she won a European Championship bronze medal in the relay along with her teammates Stephanie Douglas, Simmone Jacobs and Paula Thomas. That year also saw her run a lifetime best in the 100 m with 11.29 secs. She reached the quarter-finals of the 100 metres at the World Championships in both Tokyo, 1991 and Stuttgart, 1993.
In 1996, Kinch earned relay selection for the Olympic Games, but was forced to withdraw due to injury.
