Diamond took up athletics whilst attending Bristol Grammar School, where she notably beat Nicola Phillips in the 1500m at Sports Day.

[2] Diamond also ran a leg of the 4 × 400 metres relay winning a bronze medal as part of a team with Kelly Massey, Charlotte Best and Meghan Beesley.

[2] At the 2010 World Junior Championships in Athletics held in Moncton, New Brunswick, Canada, Diamond made the final of the 200 metres and finished in sixth position with a time of 23.62 seconds.

[5] This result lead to her being selected as a reserve for the women's 4 x 400 metres relay squad at the Great Britain at the 2012 Summer Olympics in London.

[3] Diamond is a member of the Bristol and West Athletic Club and also represents Loughborough University where she is coached by former international 400 metres runner Jared Deacon.