Brantz, born in Queensland to Dutch parents, began a modelling career in 1985 while attending St Peters Lutheran College in Indooroopilly, which continued through her time at Charles Sturt University.

During the 2006–2007 summer season, Brantz presented a weekly highlights show of the National Basketball League on the Nine Network, which began on 15 October 2006.

She was also the host for New South Wales viewers of the Shute Shield, as well as the international Hockey, Football, Golf and Basketball coverage.

In 2016, Brantz became a freelancer and took on lead commentary duties for the Westfield W-League with Fox Sports, joined ESPN as a regular contributor on their digital platform as well as presenting the US Open Primetime show from Flushing Meadows in 2017.

She has continued with the ABC, presenting their WWI commemorations from Villers-Bretonneux, Fromelles and Pozieres, Polygon Wood and Be’er Sheva as well as the Australia Day formalities in Canberra and the Australian Women's Open Golf coverage.