She has appeared in various television series, and is known for roles including Tanya in Early Doors, Janice Piper in Clocking Off, Maggie Coldwell in the BBC medical drama Casualty and Wendy Posner in the ITV soap opera Emmerdale.

Cookson portrayed the role of Maggie Coldwell on the BBC medical drama Casualty from 2005 to 2009 (this was Cookson's second role on the programme after appearing as recurring character Julie Day.

[2] She also appeared in the BBC soap opera Doctors as Kath Wylie for three episodes in 2009.

[2] From 2019 to 2025, Cookson portrayed the regular role of Wendy Posner in the ITV soap opera Emmerdale.

[2] Cookson won "Fave Female" of Series 21 of Casualty in the 2007 Holby TV awards.