Yee-Fui's research centres on strengthening political institutions and enhancing executive accountability. Her work has focussed on the regulation and accountability of actors and institutions in the shadows of government, such as ministerial advisers, lobby groups and government corporations, utilising empirical, doctrinal and comparative methodologies.

Yee-Fui is the author of The Rise of Political Advisors in the Westminster System (Routledge, 2018) and Ministerial Advisers in Australia: The Modern Legal Context (Federation Press, 2016), which was a finalist of the Holt Prize. Dr Ng also co-authored Douglas and Jones's Administrative Law (Federation Press, 8th ed, 2018). She has publications forthcoming in leading Australian and international books and journals, including the Law Quarterly Review, Public Law, Melbourne University Law Review, The Oxford Handbook of the Australian Constitution, and The Oxford Handbook of Political Executives.

Dr Ng was the winner of several awards, including the Monash University Faculty of Law Dean’s Award for Excellence in Research by an Early Career Researcher (2019), RMIT Graduate School of Business and Law Outstanding Early Career Researcher Award (2016), and RMIT Graduate School of Business and Law Research Impact Award (2016). She was also awarded the Monash Silver Jubilee Postgraduate Research Scholarship, as the highest ranking PhD applicant in the University, as well as the Monash Postgraduate Law Dean's Award, as the top-ranking PhD applicant in the Monash Law Faculty.

Yee-Fui's work has been recognised by the federal government and Parliament. She was invited to deliver the Senate lecture at Parliament House in 2017, where she presented on the accountability of ministerial advisers. She was also invited to give evidence to federal parliamentary inquiries into political donations and freedom of information. She has provided training to senior military officers on dealing with ministerial advisers at the Centre for Defence and Strategic Studies.

Yee-Fui has co-written key reports for the New South Wales Independent Commission Against Corruption and the New South Wales Electoral Commission on the regulation of political lobbying, and the Commonwealth Attorney-General's Department on the federal government's use of automation and new technologies and its implications for the integrity law frameworks. She has received research funding totalling $220,000 from federal and State governments, universities and international organisations.

Dr Ng is a prolific commentator on contemporary political issues in both electronic and broadcast media, including in The Conversation, ABC radio and SBS television. In 2017, Yee-Fui was the winner of the RMIT University Media Star of the Year Award for the College of Business.

Dr Ng is a Victorian Convenor of the Electoral Regulation Research Network. She has previously worked as a Policy Adviser at the Department of the Prime Minister and Cabinet, a Senior Legal Adviser at the Victorian Department of Premier and Cabinet, as well as a Manager at the Victorian Department of Justice. Yee-Fui has also practised as a solicitor at top tier law firms in Melbourne, London and Canberra, and has researched and taught at the Australian National University and RMIT University.