[4][5] On television, she has starred in programmes such as: Taggart in 1992 as Alison Bain, a TV journalist appearing alongside Mark McManus in Ring of Deceit, Wire in the Blood, Life Begins, Monarch of the Glen, Rebus, NCS: Manhunt, Auf Wiedersehen, Pet as Heather Lane,[6] Mayo, as Hope Hendrick, Holby City as Kathryn MacKenzie, A Touch of Frost as Martine Phillips, New Tricks as Lulu Questor, The House of Eliott as Francine Baily.
She appeared in two Midsomer Murders episodes; “Death In Chorus” (2006) as Carolyn Armitage and “The Flying Club” (2014) as Miranda Darnley.
She played American journalist Winifred Bonfils Black in ITV's 2013 Mr Selfridge, and Susie Parks in the 2017 BBC One drama TV series Doctor Foster (episodes 1–2, 4–5).
An associate of Connie Beauchamp, Cornell is involved in removing a cancerous tumor from her heart and saving her life.
In 2020, she appeared in episode 3.3 "The Sticking Place" of the BBC TV series Shakespeare & Hathaway: Private Investigators.
In 2022, she appeared as Lady Margot Hawthorne in episode 9.6 "The New Order" of the BBC TV series Father Brown.
Her work in film includes: The Road to Guantanamo,[9] A Cock and Bull Story, Batman Begins (as Martha Wayne), London Voodoo, The Winslow Boy[10] and Mrs.