Playing for Sheffield FC in the 2017–18 FA WSL 2, Johnson finished as second top-scorer in the league with 12 goals in 15 appearances in the second-tier competition.[3] She was named WSL 2 Player of the Month for January 2018[4] and again in May 2018.
In October 2019 she attracted attention after scoring three hat-tricks for Aston Villa in the opening five games of the 2019–20 season[6] earning a nomination for the September FA Women's Championship Player of the Month award.[3] While the season was uncompleted after 14 games due to the COVID-19 pandemic, at the time of the competition's completion Johnson was the second top-scorer with 12 goals.[7]
Johnson returned to Sheffield to represent Sheffield United in August 2020, scoring five goals for the club in 15 league appearances in the 2020–21 season. Johnson announced her departure from Sheffield United in May 2021.[8]
On 10 August 2021, it was announced that Johnson had joined recently relegated Bristol City ahead of the 2021–22 season.[9] She left during the summer in 2022 to join Charlton Athletic.[10]