NSW Nepal Earthquake - Can We Bring Mother to Sydney?

I am a 485 visa holder, I am on a dependent visa. Me and my 2 sisters are in Sydney. My elder sister is in 485 visa as well, primary applicant and is planning to move to regional NSW, Dubbo. My younger sister is studying bachelor of accounting at one of the leading universities, Sydney campus and is on final semester of her 1st year diploma.

As you are aware of the current situation in Nepal due to earthquake, 3 of us here are devastated and have been crying since the day. The pain we are going through cant be described. My mother is alone is Kathmandu. The situation there cant be compromised and 3 of us going there leaving everything here is bit scary. My younger sister is in a messy condition. She is preparing for her final semester and we would love to have our mom by our side here in Sydney.

Is there any option to bring our mom here? We are ready to show and pay whatever needed financially here in Sydney. All the health requirement arrangement would be done through private health cover.

All we need is to be with our mom who is facing such a crisis alone in Kathmandu, Nepal in absence of her 3 dear daughters because of whom we are what we are today and are where we are today.

Will you please give me some options on how can i apply for my moms visa. I checked in Department of Immigration and Border Protection, but could not find it. I learnt and heard somewhere that if more than 50% of the children are in Australia then there is one visa for parent to come and join them in sydney. The reason we want our mom to come and join us is we want to be with our mom and give her emotional support when she needs it the most.

Please help me and please guide me what to do. All the offices and things are destroyed in Nepal. The condition is Chaotic. So we were thinking of applying for her visa from here. We all are going through traumatic effect here and mom is alone there so its hard to imagine how she is managing there.

Your advice could change our lives.