[3] She played her first matches for the team at senior level in 2020, appearing in two friendlies against Scotland without batting or bowling.
[6] She played three matches for North Representative XI in the tournament before making two appearances for Lancashire, both against Cumbria, but made little impact.
[10][11] Mullan was also named as part of North West Thunder's squad for the 2020 Rachael Heyhoe Flint Trophy, but did not play a match for the side that season.
[3] She made her debut for the side in the 2021 Charlotte Edwards Cup against Western Storm, making 2 runs.
[19] Mullan went on loan to The Blaze from North West Thunder for the first six rounds of the 2024 Rachael Heyhoe Flint Trophy, scoring 47 runs in her four matches.