[2] In 1963, her father Bob wrote the book The Affluent Sheep, having researched around 500 families, which claimed that most housewives shopped with "unwarranted complacency" about prices.

[8][9] Millar began in journalism as a trainee on the Mirror Group Graduate Training Scheme in the West Country, later moving to the Daily Express, where she worked as a news reporter and lobby correspondent.

She was a freelance journalist between 1988 and 1995, contributing to the Daily Express, the Sunday Mirror and The House magazine, Parliament's in-house publication.

In 1993, she co-authored (with Glenys Kinnock) By Faith and Daring, Interviews with Remarkable Women, to celebrate the tenth anniversary of Virago Press.

[18] However, in April that year, she confirmed that she would not be running in for the selection, telling the Evening Standard: "I have decided I want to stick to campaigning on schools issues".

In an op-ed for The Guardian in August 2018, Millar wrote about her dilemma over whether to leave the Labour Party after over 40 years: "The most pressing reason is Brexit.

Millar said "it was a mistake not to adopt the internationally recognised definition of antisemitism", surmising that "Corbyn is completely unsuited to being prime minister."

I have searched in vain for any far-reaching ideas that might disrupt our current market-driven, hierarchical school system – my particular area of interest.

Without drastic change to current education policy Corbyn's banal rhetoric about fairness and equality is just hot air.

[27][28][29] Millar received the Fred and Anne Jarvis Award from the National Union of Teachers in 2009 for her campaigning for good-quality local comprehensive schools as against academies.

[12][34] Millar became a trustee of the Camden Abu Dis Friendship Association in October 2020, a charity which aims to promote human rights in Palestine.