Wrong! A grandaughter is completely different mate thats why you registered her. And unlike many countries Australia will offer emergency care i.e they wont let you die. Unfortunately for a foreign resident, and this is straight of the gov.au website
When in Australia and health care assistance is required, and a person is not covered by an appropriate level of private health insurance cover, as a non-resident and non-citizen of Australia, a person will be considered a private patient and will be required to pay any costs themselves at the time of treatment.Feb 7, 2565 BE