Hmm, I'm not sure if I understand everything correctly. But I think you will go alone, your mother will take care of your 3 children and at the moment you don't know how long you will stay in Australia. That's a pretty big step, but I guess you can earn a lot more money there to support your family. Well, you will be separated from them alone in a foreign country. When will you leave? I think you should brush up your English skills a bit before you go.