A senior Aboriginal woman from the Illawarra district of New South Wales, traditional lands of the Wadi Wadi people, Barbara was born on the Kemblawarra reserve at Port Kembla. As a mature age student she graduated from the University of Newcastle with a triple major in English Literature. She later went on to teach Aboriginal Studies at the University of New South Wales, a position she held for five years. Following this she took up a position at Wollongong University and was eventually appointed to as a Senior Honorary Research Fellow in the Faculty of Law at Wollongong University (UoW), an appointment she has filled since 1999. Nicholson taught Aboriginal students in State Correctional Facilities and has undertaken casual consultative social research with independent social research companies. In 2014, Nicholson was awarded an honorary Doctor of Laws at Wollongong University.
Outspoken on the issues of land rights, assimilation and criminal justice, Aunty Barbara has been active in many Aboriginal organisations, is an executive member on the committee of the Link-Up NSW Aboriginal Corporation, and has (or had) affiliations with The National Aboriginal History and Heritage Council, the Indigenous Social Justice Association, the Illawarra Aboriginal Medical Service, the Wadi Wadi Coomaditchie Aboriginal Corporation and was president of The Aboriginal Deaths in Custody Watch Committee for five years. Source: Sighted 25/07/2007). In 1997 Aunty Barbara was a key figure in setting up the "Signature Sorry Campaign" in Bowral following the release of The Bringing Them Home Report and which culminated in the Sorry Books around the nation.
Aunty Barbara has had significant input to the cultural content of numerous academic texts and in 2010 was serving in her fifth year as Cultural Advisor on the Human Research Ethics Committee at University of Wollongong. During 2010, she established an Elders in Residence program at the Woolyungah Indigenous Centre at the University of Wollongong, which operates to offer cultural support to both students and staff at the centre. In August 2009, Aunty Barbara was nominated for the 2009 Aboriginal Justice Award from the Law and Justice Foundation of New South Wales.
Aunty Barbara had contributed to the organisation of, as well as participating in, the annual Celebrating the Voice (CTV) readings in Wollongong since its inception in 2000. CTV is specific to Indigenous cultures including Canada and New Zealand. In 2008 CTV toured the Far South Coast with readings in Bermagui, Moruya, Bateman's Bay and Nowra. In 2009 CTV travelled to Wagga Wagga, Naranderra TAFE, Junee Correctional Centre, where she held workshops with the inmates and Albury for a schools visit and participation in "Write Around the Murray".
She serves on the Board of the South Coast Writers Centre and is a member of the Black Wallaby Indigenous Writers Group and the First Nations Australia Writers Network.