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
Gina Prinz
Miranda Kador
Roswita Mader
Sybille Wildering
Hannah Falck
Heike
Self
Judith Stoll
Brida
Sara Schiller
Diana Weininger
Jeanette Wilson
Self
Ulrike Gronau
Lucie Thieme
Sonja Omminger
Katharina Diemel
Manuela
Frieda Borck (Folge 1)
Brida
Clara Andersen
Nursing Home Manager
Nanna
Alma Mahler
Anita
Ella
Emma Turgut
Katharina
Milena 'Milli' Neubert
Laura
Magdalena
Therapist
Meta Jurkschat
Deirdre Lawless
Julia Brandt
Mercia
Caroline Mathilde
Mel
Agnes, junge Frau in Auschwitz
Lisa Sobiri
Kellnerin
Maja Hönow
Gretchen Dutschke-Klotz
Tascha
Mizzi
Therese Maxeiner
Jakobs Tochter Mascha
Lilly
Jana Skoff
Martha Müller
Miriam
Self