Allen was born in England in 1941 and after graduating from the University of Grenoble in France launched her career in the fashion department of Queen Magazine in 1961.
She moved to British Vogue two years later where she spent 10 years writing and editing the Young Idea pages at the height of London's Pret-A-Porter revolution.
Allen set up the Bachelor's degree course in journalism at Central St Martin's Art College in 1973 before segueing into costume design on Don't Look Now at the behest of Nic Roeg.
During the course of a 33-year career she worked on films such as Eyes Wide Shut, Little Shop Of Horrors, The Witches, White Mischief, Dead Man, A Kiss Before Dying and Love In The Time Of Cholera.
Allen is survived by her son Ben, daughters Lucy and Holly, her sister Kari and grandchildren Emily and Mia.