Thornberry is a trained barrister was active since 1985 to 2005, specializing in human rights law under the guidance of Michael Mansfield. In 2001, she became a candidate in a general election, in which she was defeated by the Conservative incumbent, Julian Brazier by 2,069 votes.
In 2005, Thornberry was elected to the Parliament, where she served from 2005 to 2010, on the Communities and Local Government Select Committee. During that time, she also spoke on both housing issues and issues relating to the Human Fertilisation and Embryology Act 2008. She also voted against the whip on issues relating to national security on several occasions.
In the general election of 2010, Thornberry again elected and appointed as a Shadow Attorney General in Ed Miliband's shadow cabinet, where she worked until November 20, 2014. Similarly, she again re-elected in the 2015 general election and appointed as a Shadow Minister of State for Employment.
While working in a shadow cabinet reshuffle, Thornberry replaced Maria Eagle and became Shadow Secretary of State for Defence. During another reshuffle, she was also selected as a Shadow Secretary of State for Foreign and Commonwealth Affairs.
She has also worked as a Shadow "Secretary of State for Exiting the European Union" from July 2016 to October 2016. After a year, she was again appointed the as a Shadow First Secretary of State in a government formed by Prime Minister, Theresa May.
Thornberry is a British by nationality and belongs to white ethnicity. She married her boyfriend, Christopher Nugee, in Tower Hamlets. Her husband, who was also her teacher, later became a Queen's Counsel, then a High Court Judge. A Queen's Counsel is a lawyer selected by the Queen, in this case, Queen Elizabeth, to guide her in matters of the law. The couple blessed with three children. She lives a happy married life with her spouse along with their children and has no any rumor of divorce between the couple.
Thornberry is a well-known personality, who had made a collection of a huge amount from her professional career. Recently, she bought a flat in Guildford, Surrey, paying £600,000. She has also worked as a member of Parliament, from which she must have collected a decent amount of salary. According to the report of mail online, her current net worth is estimated to be £2.9 million.