Maryanne has resided in the Heathcote electorate for more than fifty years and currently resides in Engadine. She was elected the Member for Heathcote following the NSW election on 25 March 2023.

The electorate of Heathcote stretches almost 50 kilometres from Kirrawee in the north to Bulli in the south. The Royal National Park – the second oldest national park in the world – is also located in the Heathcote electorate.