Devlin signed her first professional contract with Arsenal in June 2016. She had been at the club since she was 14 having joined from the Millwall Centre of Excellence, and helped Arsenal's development squad to a league and cup double in 2015/16.[2]
Millwall Lionesses
Devlin initially returned to Millwall Lionesses on loan for the 2017 Spring Series, scoring the winner in a 2–1 victory against London Bees in her first game with the club.[3] The move was made permanent prior to the start of the 2017–18 season.[4] In the one full season she had at Millwall, Devlin led the team in goals with 9, making her the fifth highest scorer in the WSL 2.
In July 2018, Devlin joined Manchester United for their inaugural season in the FA Women's Championship. She made her competitive debut for Manchester United, as an 89th minute substitute for Lauren James, in a 1–0 League Cup victory against Liverpool on 19 August, and her Championship debut in a 12–0 win against Aston Villa on 9 September.[5][6] She scored her first goal for United on 4 November in a 4–1 win over Tottenham.[7] She was released by the club at the end of the season having made 21 appearances.[8]
Charlton Athletic
On 9 August 2019, Devlin signed with FA Women's Championship team Charlton Athletic for the 2019–20 season.[9] Devlin made her debut in their opening game on 25 August 2019, playing the full 90 minutes in a 0–0 home draw with Lewes.[10] On 15 September, Devlin was sent off after receiving two yellow cards in Charlton's 2–0 league loss to London City Lionesses.[11]
Leicester City
Devlin signed an 18-month contract with fellow Championship side Leicester City on 8 January 2020.[12] Devlin made her debut in a 1–0 league loss against Durham on 12 January 2020.[13] The team won the 2020–21 FA Women's Championship title, earning promotion to the FA WSL for the first time in their history.[14] On 4 June 2021, Devlin signed a new two-year contract.[15]
She has also played for the country at under-19 level and was part of the team that lifted the Women's International Cup in 2016 having won all three tournament games against France, Northern Ireland and USA.[22]
In January 2019, Devlin was a late addition to Mo Marley'sUnder-21 training camp at St. George's Park.