In the event of a changing visa application information, this is how it is done. The Australian spouse visa for a Thai national does take a while to complete as much as the Australian fiancée visa for a Thai national. During this time certain facts might have changed and the Embassy needs to be updated about this. There are a number of instances where facts on the application form has changed. Below are a few of them as an example.
If you are applying for an Australian visa be it a spouse visa or fiancee visa then they can ask you to come in for an interview. This is the dreaded Australian visa interview. When you go in for an interview they will ask you to bring with you your passport (her passport) as well as any documents which are short in the application process. They will normally give you a list of documents which they still need. This is not uncommon when you apply for a visa yourself.