In 1961 she played the part of barmaid Nona Willis in Granada's twice-weekly serial Coronation Street and appeared also in episodes of The Cheaters (1962) and Zero One (starring Nigel Patrick, 1963).
Ferris's films included the drama Term of Trial (1962) starring Laurence Olivier, A Pair of Briefs (1962), a romantic comedy set around the Inns of Court; Sparrers Can't Sing (1963) as Nellie Gooding; A Place to Go (1963) starring Rita Tushingham and Bernard Lee; Bitter Harvest (1963) with Janet Munro and John Stride; Children of the Damned (1964) starring Ian Hendry, in which a group of children brought to London by UNESCO turned out to be humans advanced by a million years; Michael Winner's The System (1964),[1] with Oliver Reed and Julia Foster, an early "Swinging London"-style sex comedy about young loafers at a seaside resort; Catch Us If You Can (1965),[2] which featured the rock band the Dave Clark Five and owed much to The Beatles' A Hard Day's Night the previous year; Interlude (1968), alongside Oskar Werner, John Cleese and Donald Sutherland, which film historian Leslie Halliwell described as "Intermezzo remade for the swinging London set";[3] and Desmond Davis's A Nice Girl Like Me (1969), in which Ferris played a young woman named Candida who kept getting pregnant ("Candida isn't much for sex but she's big on babies" as one critic put it[4]).
Despite the controversial subject matter, which included a scene in which a baby was stoned to death in its pram, the case was a step towards the Lord Chamberlain's losing his censorship role under the Theatres Act 1968.
Depicting the tensions and rivalries among a provincial repertory company rehearsing The Beggar's Opera, the Washbrooks' daughter Linda was played by a young Patsy Kensit.
Equally, although ostensibly she fitted the stereotypical image of a mid-1960s blonde, she was never really a "starlet", a characteristic she shared with, among other actresses of a similar mould, Julie Christie and Carol White.