My name is ***** ***** I am a NSW Solicitor. Thank you for your question, and will do my best to assist you with your question. Please understand this is not legal advise but a guide to assist you.
I assume you are still in Australia. Because you say you have court orders 5 years ago fro the children I will assume you have been separated for 5 years.
You can apply for a divorce in Australia provided you have been separated fro the 12 months and currently living in australia.
A copy of the marriage certificate will be required. You do not have to go to the US and get a divorce.
Here is the link for divorce in WA and it contains the forms you need
I hope this makes sense and is of assistance. If there is nothing further
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