[6] Her younger sisters are Susie, who is mentally and physically disabled as a result of being deprived of oxygen at birth,[7] and Nicola, a former actress who appeared in the 1996 British TV production of The Fortunes and Misfortunes of Moll Flanders, in which Kingston starred.

[citation needed] In 1980, Kingston made her television debut in three episodes of the children's drama series Grange Hill, while also appearing as an uncredited extra in the film The Wildcats of St Trinian's.

[9] Her classic Shakespearean roles included Calpurnia in Julius Caesar (1987), Cordelia in King Lear (1990), Hero in Much Ado About Nothing (1990–1991), Titania in A Midsummer Night's Dream (1992) and Desdemona in Othello (1993).

In film, she appeared in The Cook, the Thief, His Wife & Her Lover (1989) with Helen Mirren, The Infiltrator (1995) with Oliver Platt and Carrington (1995) with Emma Thompson, where she played writer Frances Partridge.

In April 1996, she got her first regular television role as customs officer Katherine Roberts in the ITV crime drama The Knock, appearing in all thirteen episodes of the second series.

[13][16] In November 2005, Kingston guest starred as a vacationer whose husband gets kidnapped by a Mexican street gang in an episode of the CBS crime drama Without a Trace, titled "Viuda Negra" and directed by her former ER co-star Paul McCrane.

She thought it was simply a one-off guest role but was delighted to find out that she would be a returning character after the story's writer, Steven Moffat, succeeded Russell T Davies as the Doctor Who showrunner.

In October, she appeared in the episode "Art Imitates Life" of the police procedural drama CSI: Crime Scene Investigation as psychiatrist and grief counsellor Patricia Alwick, who helped the team cope with the recent death of one of their members.

[29] Following a nomination for Best Actress at the Manchester Theatre Awards,[30] she reprised her role with Branagh at the Park Avenue Armory in June 2014, making her New York stage debut.

[31] Earlier in April, Branagh and Kingston took other classic Shakespearean lead roles in the two-and-a-half-hour adaptation of Antony and Cleopatra, broadcast on BBC Radio 3 as part of its celebration of the 450th anniversary of Shakespeare's birth.

[32] During the late 2010s, she took a prominent role as Sarah Bishop in Sky's fantasy drama A Discovery of Witches (2018–2022), while also appearing in shows like Gilmore Girls: A Year in the Life (2016),[33] Shoot the Messenger (2016)[34] and The Widow (2019).

[8] In 2021, she wrote a River Song novel called Doctor Who: The Ruby's Curse for BBC Books,[35] and reprised the role for pre-recorded elements of the interactive theatrical experience Time Fracture.