The Student Guardian Visa (subclass 590) allows you to stay in Australia as the guardian of an international student (you can care for more than one student) younger than 18 years of age studying in Australia on a Student Visa. You will also be permitted to study an English Language Intensive Course for Overseas Students (ELICOS) for less than 20 hours per week, or study another course for up to three months.
The Student Guardian Visa does not generally allow you to work.