[2] Called to the bar in 1992, Blackwell was a junior counsel in the team conducting the prosecution of the British serial killer Harold Shipman.

Blackwell was "vilified" by the media in 2013 when a complainant in a rape case committed suicide a week after cross-examination by her in court.

[9][10] In 2016, Blackwell was lead barrister for the successful prosecution[11][12] of former Sunderland footballer Adam Johnson at Bradford Crown Court.

[20] During Module 1 of the United Kingdom Covid Inquiry, Blackwell examined former Prime Minister David Cameron[21] and former Chancellor George Osborne[22] After attending Loreto Grammar School in Altrincham, Greater Manchester (1981–88), Blackwell studied Law at the University of Birmingham (1989–92) and subsequently went to the Inns of Court School of Law in London where she completed the Bar Vocational Course.

[citation needed] A keen member of the National Youth Theatre, she performed in Murder in the Cathedral by T. S. Eliot at The Edinburgh Festival in 1982.