She also held senior positions in journalism, serving as publisher and deputy editor-in-chief of the Ming Pao newspaper; and as a columnist for South China Morning Post.

She has written several volumes of critical studies on the wuxia novels of Jin Yong and earned her Doctor of Philosophy degree from Boston University.

[3] On 18 April 2020, Ng was arrested as one of 15 Hong Kong high-profile democracy figures, on suspicion of organizing, publicizing or taking part in several unauthorized assemblies between August and October 2019 in the course of the anti-extradition bill protests.

[6] On 12 April 2024 Margaret Ng (then aged 76) received from the Hong Kong Court of Final Appeal a suspended sentence following conviction for taking part in an unauthorised procession in August 2019.

[8] On 29 December 2021, Ng and six other people linked to Stand News were arrested on suspicion of breaching a colonial-era law covering conspiracy to print or distribute seditious materials that were supposedly published at the pro-democracy outlet.