[5] Her subsequent career has seen her cast as a number of iconic historical and fictional figures including Scarlett O'Hara in Scarlett (CBS, 1994), Jackie Kennedy in Jackie Bouvier Kennedy Onassis (CBS, 2000), Queen Mary I in The Virgin Queen (BBC, 2005) and Catherine of Aragon in Wolf Hall (BBC, 2015).
As a child actress, from 1974 to 1979, Whalley made a number of television appearances including bit parts in popular soap operas Coronation Street and Emmerdale.
Her television work continued with early appearances in episodes of popular series including Juliet Bravo and The Gentle Touch.
That same year she made a non-speaking appearance as a groupie in Alan Parker's musical drama Pink Floyd – The Wall (1982), featured in Stan Barstow's well-received TV series A Kind of Loving (Granada, 1982) and starred as Gilly Brown alongside Trevor Eve in Danny Boyle's production of The Genius at the Royal Court Theatre.
[4][7] At this time, she was also the lead singer of the pop group Cindy & The Saffrons; they recorded the Shangri-Las' song "Past, Present and Future" in 1982 at Abbey Road Studios, and the track made the UK singles charts, peaking at #56.
Her work for the English Stage Company at the Royal Court Theatre continued with performances as Pam in Danny Boyle's production of Saved and June in Max Stafford-Clark's The Pope's Wedding from 1984 to 1985.
[4][7] Whalley found early success on British television with a lead role in Troy Kennedy Martin's highly regarded and influential drama serial Edge of Darkness (BBC, 1985), for which she received a nomination for the BAFTA TV Award for Best Actress.
Further television success came with the key role of Nurse Mills in Dennis Potter's drama serial The Singing Detective (BBC, 1986).
[3] She concluded her work with the Royal National Theatre that year by performing as Euphie and 1st Cutie in Peter Gill and John Burgess's The Women.
[4][7] Whalley met the American actor Val Kilmer in 1987 while filming her first US lead role in George Lucas and Ron Howard's Academy Award nominated fantasy adventure Willow (1988).
Her most notable British film role to date was as Christine Keeler in Michael Caton-Jones's historical drama Scandal (1989), a fictionalised account of the Profumo affair, which screened in competition at the 1989 Cannes Film Festival, featuring John Hurt as Stephen Ward and Sir Ian McKellen as John Profumo.
After her divorce from Kilmer in 1996, she changed her surname back to Whalley, starting with her lead role in Jon Amiel's spy comedy The Man Who Knew Too Little (1997) starring Bill Murray.