Speed made her county debut in 2016, for Essex against Nottinghamshire, scoring 7*.[3] In 2018, she helped her side to promotion from Division 3C of the Twenty20 Cup.[4] In 2021 she took her maiden county wickets, both against Kent in consecutive games on 9 May.[5]
Speed played for Huntingdonshire in the East of England Championship in 2020 and 2021, including hitting 62 from 53 balls in a match against Hertfordshire in the 2020 tournament.[6] In 2022, she only played for Essex, playing two matches in the Twenty20 Cup, scoring 45 runs.[7] She played four matches for the side in the 2023 Women's Twenty20 Cup, scoring 47 runs and taking one wicket.[8][9]
In 2021, Speed was selected in the Sunrisers squad for their upcoming season.[10] She made her debut for the side on 29 May, against South East Stars in the Rachael Heyhoe Flint Trophy.[11] She was ever-present in Sunrisers' 2021 Charlotte Edwards Cup campaign, scoring 60 runs including her Twenty20 high score of 26*.[12][13] She played four matches for Sunrisers in 2022, across the Charlotte Edwards Cup and the Rachael Heyhoe Flint Trophy.[14][15] She was again in the Sunrisers squad in 2023 and 2024, but did not play a match in either season.[16]