Cox was born to a British father and an Irish mother in Vienna. Her parents later divorced. Both of them are pianists, who originally came to Vienna on a grant for musicians. Cox grew up in Vienna and graduated from high school in 2003. She developed an interest in acting after performing in a play as part of her English classes during her final year in high school. After her graduation she went on to study acting at the Max Reinhardt Seminar. In 2008 she was under contract as a stage actor at the Theater in der Josefstadt in Vienna. In 2011 Cox moved to Berlin and since then she has appeared in various movies and series on German and Austrian TV, among them several Tatort movies. Since 2015 she plays the role of the viking woman Brida in the TV series The Last Kingdom, which made her known to international audiences.
Edith Egger
Self
Miranda Kador
Roswita Mader
Sybille Wildering
Hannah Falck
Gina Prinz
Heike
Brida
Judith Stoll
Lucie Thieme
Diana Weininger
Ulrike Gronau
Sara Schiller
Katharina Diemel
Jeanette Wilson
Manuela
Self
Sonja Omminger
Brida
Frieda Borck (Folge 1)
Nursing Home Manager
Nanna
Clara Andersen
Alma Mahler
Mercia
Therapist
Agnes, junge Frau in Auschwitz
Anita
Deirdre Lawless
Katharina
Lilly
Mizzi
Ella
Maja Hönow
Martha Müller
Self
Emma Turgut
Jana Skoff
Magdalena
Mel
Laura
Therese Maxeiner
Jakobs Tochter Mascha
Milena 'Milli' Neubert
Lisa Sobiri
Kellnerin
Miriam
Caroline Mathilde
Gretchen Dutschke-Klotz
Julia Brandt
Meta Jurkschat
Tascha