how long you had moved to HK as your resident? as what i know, some countries also need to see do you really live in country during your marriage. if you got married in Aust. but then moved to HK for a long time, you might able to do it in HK thur HK lawyer could be under HK law as well for the kids right as your a a full time mom.
example: ppl got married in HK , they can divorce in canada or USA. they have to seperate house and money 50/50 under the local law!