She is the daughter of Michael D. Higgins, a former Labour Party politician and current President of Ireland.

[8] In 2016, Higgins introduced a motion to the Seanad calling on the Irish Government not to sign up to provisional application of the Comprehensive and Economic Trade Agreement (CETA), citing the investor court system elements of the treaty's potential impacts on public services, the environment and policy decisions.

[10] In December 2020, journalist Miriam Lord named Higgins 'Senator of the Year' "for her tireless approach, collegial outlook, level of research, grasp of detail, participation in debates and undimmed enthusiasm for the job.

[10] In 2021, Higgins introduced a motion to support the TRIPS Waiver on the COVID-19 vaccine, which was passed in the Seanad.

Journalist Miriam Lord said Higgins’ work on the Bill “won universal praise” and that she “saw the global picture, knew her subject inside out, was detailed and logical and spent hours in the chamber.” [13] In 2023, Higgins introduced the Climate Action and Biodiversity (Mandates of Certain Organisations) Bill, which would give Coillte and Bord na Mona - two of the largest landowners in Ireland - mandates for nature and climate action.