She is clinical director of acute and network-oriented care at Pro Persona, a large institution for mental healthcare in The Netherlands. In addition, she is program leader of the Research group Forensic Mental Health Care at GGzE and clinical psychologist at De Catamaran, hospital for youth forensic psychiatry & orthopsychiatry. Van Nieuwenhuizen studied clinical and experimental psychology at the University of Groningen. In 1998, she got her PhD in Medicine at the University of Amsterdam. In 2004, she was officially registered as psychotherapist (behavioural therapy and psychoanalytic therapy), in 2016 as MH-psychologist (children & youth) and in 2021 as Clinical psychologist.