Baby sitting is good, walking people's dogs, taking care of pets, maybe if you know some elderly folks you can help them clean. I guess I am out of ideas that is a hard one, but there's some more ideas. Try different things until you make money I guess. There is always a paper route.
Unfortunately the economy in Tasmania is not the ideal place for a person your age to be looking for work. Try retail businesses or child care (babysitting) in your area.
Don't let this interfere with completing your education in case you have to move off the island to find work when you grow older.