She was the Country Liberal Party member for Katherine in the Northern Territory Legislative Assembly from 2003 to 2008.
In South Australia she had worked in clerical positions and in Katherine she was an office manager before she and her husband purchased Red Gum Tourist Park.
She was deputy leader of the CLP for a period and served on the front bench.
In 2006 she was involved in a car accident and sustained serious injuries, which was a contributing factor towards her retirement in 2008.
In the 2021 Australia Day Honours Miller was appointed a Member of the Order of Australia for "significant service to local government, to tourism, and to the community of Katherine".