Parnell is an insights and advocacy strategist for policy change campaigns and a senior fellow at the Centre for Independent Studies. She has worked on policy and communications for political parties in Germany and Australia, and run influential campaigns on topics ranging from school choice through to productivity reform. She is a non-executive director and chair of the risk and compliance committee for an educational institution and serves on the advisory board of Australians for Prosperity. She writes a weekly column for the Sun-Herald and the Sunday Age on politics, policy and culture.