Tourist Visa to Australia for Laos Passport holder living in the UK [closed]

We are planning a trip to Australia for a month over Christmas.... Myself, our two children and my parents, all of whom are UK passport holders plus my wife who is still traveling on her Laos passport. We live in the UK and she has indefinite leave to remain here but as yet no UK passport.

Have looked on the Australian Gov website and it seems that we will need to apply for a Visitor visa (subclass 600) for her with the rest of us applying in the usual way for the electronic one.

We will be staying in a house owned by my parents whilst we are there, having traveled there as a family and will all be returning back to the UK together for the kids to start school again in January.

I'll be calling the Australian embassy in London next week, however some very cheap flight tickets have become available and I won't be able to speak to the embassy before I need to make the decision on the tickets, which are non refundable....

Does anyone know the likelihood of them granting a tourist visa in this situation? We've had several Schengen visas and also a US visa in the last couple of years for the various holidays we have taken but I have no idea whether it would just be a straightforward application process for Australia or if its extremely difficult to get visas for passport holders of countries not on the pre-approved list and eligible for the electronic visa....

We live in Scotland so there isn't even a consulate that we can visit here to ask for advice either, hence having to call London....

Any advice or experience or suggestions?