First of all, big hugs. Mental illness is horrible for all affected by it.
I can't help with specific services in either QLD or Victoria. But I had a look and found some links and numbers that may be helpful. Sorry I can't help more.
Some of these my partner and/or myself used, some I have used the NSW equivalent and some I just researched when I came across this.
I understand this must be so so hard for you, and the fact that her age is putting so many roadblocks in front of you is ridiculous.
This may be a little overwhelming, but these are all current, valid and may be able to help. I hope they do!
Some about social security appeals and mental health -
Administrative Appeals Tribunal - independently assesses appeals against government bodies
Handles social security issues
Fact sheet about mental illness and centrelink (the whole site is helpful though) -
Social Security Appeals Tribunal -
Assesses complaints and appeals against Centrelink
Mental Illness and Advocacy -
An organisation that connects people with mental illnesses to supports that they need - social, financial, medical etc
Crisis Assessment Teams and Psych Triage Vic -
You probably already know about this, but if you have immediate concerns for your daughter you can call these to get her assessed and treated ASAP
Anxiety Disorders Association VIC -
Have a wide range of support, both online and in person.
For you -
ARAFMI - National carers of mental illness sufferers network. They offer online and phone support, and can probably assist you to find any more assistance or advice as well as be there when you need to debrief or stress to someone.
Commonwealth Carers and Respite -
May be able to help you advocate for your daughter
Carers Australia - Provides info, support and advice for caring for anyone of any age and illness