Abi was born in Westminster, London to Nigerian parents. Her name "Adesola" means "crowned with wealth" in Yoruba. She attended Bentley Wood High School. She represents Shaftesbury Barnet Harriers athletics club. Her first outing to a major athletics came at the 1998 World Junior Athletics Championships, where she finished fourth as part of the British 4 x 100 m relay team. She continued to perform well at the junior level, but her progress was interrupted in 2000 by an injury. She managed to bounce back the following year, with her comeback including a silver medal at the European under-23 Championships.