Thank you!
Another question I have is that my mum is ready to come to Australia now whereas my fathers still working and not yet retired. Is my mum able to come and live in Australia now using her 173 visa and my dad come later in say another 6 months or so? Does it matter if my mum's not the primary applicant for their 173 visa, does she still have the same rights as the primary applicant to come and live here etc even if the primary applicant doesn't do the same?