Anderson was born in St Vincent but was educated in Dulwich, South London at James Allen's Girls' School and was a resident of Catford, London.^{[citation needed]}

Anderson finished third three times at the AAA Championships, behind Jamaican Evadnie McKenzie in the 100 metres event at the 1997 AAA Championships,^[2] third behind Joice Maduaka in the 200 metres at the 1999 AAA Championships and third behind Sarah Wilhelmy at the 2000 AAA Championships.^[3]

At the 2000 Olympic Games in Sydney, Anderson represented Great Britain in the 100 metres and 4x100 metres events.^[4]

After a second place finish behind Sarah Reilly at the 2001 AAAs, she finally became the British 200 metres champion after winning the AAA Championships title at the 2002 AAA Championships.^[5][6]

Shani now coaches athletics from club to Olympic level and started her own personal training company, Anderson Fitness Consultants. She has a personal training studio at The Armitage on Great Portland Street where she trains clients and she also runs corporate health & wellbeing events and programmes.^{[citation needed]}