457 visa

We are about to apply for 457 visa, we have application filled out. However my girlfriend is waiting on police checks to come back from Germany and USA. My girlfriend is the main visa applicant, i will be on the visa aswell as a de facto, we are still trying to sort of evidence of our relationship.
It is possible to submit the application now before we have the relevant documents needed ie police checks and relationship evidence?

We are pretty much just waiting for the letter from United States to come which seems like forever, we just werent sure if we can submit the visa application now without the documents.

Any help would be great