Bromiley played a role in a Hollywood film before returning to the UK where, in 1954, she started work as assistant stage manager at the Central Library Theatre, Manchester; followed by a West End stage role in The Wooden Dish directed by the exiled US film and theatre director Joseph Losey (who became Bromiley's husband from 1956 to 1963).
They have a son by this relationship, the actor Joshua Losey.
Since 1963 Bromiley has lived with the Dublin-born actor and writer Brian Phelan (who appeared in the 1965 film Four in the Morning), they have a daughter, Kate.