Having grown up with a strong sense of social justice,[4] she was the campaigns co-coordinator at the British Section of Amnesty International from 1980 to 1985, and was twice elected as a Labour Councillor for East Finchley in the London Borough of Barnet, serving from 1982 to 1990, leading on housing and planning and holding weekly surgeries.

[1][5] During her career she worked with nearly 20 different cabinet ministers responsible for prisons and finds that the barriers to reform change with the government and politics of the day.

[5] She has spoken publicly and written in a range of media[6][7] to highlight 'the most despicable and nastiest' rules such as banning of books in prisons.

[13][3] In 2009 she was appointed an NHS non-executive director of Barnet Primary Care Trust, responsible for a budget of £550 million delivering health services to 350,000 people.

Crook was appointed Officer of the Order of the British Empire (OBE) for services to youth justice in the 2010 New Year Honours.