She completed her LLM at Victoria University of Wellington in 1992 on a scholarship of the German Academic Exchange Service, studying inter alia environmental law under Sir Geoffrey Palmer.

[9] She was a Scholar-in-Residence for prominent law firm Wilmer Cutler Pickering Hale and Dorr in 2015, 2018 and 2019,[10][8] and an invited guest of the Max Planck Institute Luxembourg in 2019.

[8] She was named in Victoria University's Honours List in 2015 and 2020, and was appointed British Insititue of International and Comparative Law Honorary Senior Fellow in 2020.

[17] Butler is a fully qualified German lawyer and a barrister and solicitor of the High Court of New Zealand.

She has been involved as a consultant expert, inter alia, in Child Poverty Action Group v Attorney General,[19] Boscawen v Attorney-General, [20] New Health Ltd v South Taranaki District Council,[21] and the Austrian litigation that ensued from the Patterson fraud.