paying board rant

So I am currently 17, live at home with my single mum. We get payments because my mum doesn't work and hasn't for years. Mostly laziness, can't stick to a job. We live off of Centrelink(for those not from Australia, it's just money from the government). My mum wants me to pay rent as soon as I start claiming my youth allowance(money from the government for me, that currently goes to my mum). I will be getting at most $230 a fortnight, she wants $80 a week. Once I start getting that, that leaves me with $35 a week. Which I'm meant to use to save for a car, moving out, transports to school, clothes etc. I am trying to get a job, but it's hard when your mum won't drive you and you don't have your licence(I'm working on getting it). She doesn't work, doesn't clean the house ever (not over exaggerating, I do everything). I also care for my 2 year old brother, who she barely looks after. All while trying to stay sane from how negative my life if with her, trying to finish school etc. I would not think that this is unfair if she helped at all with anything. But she does nothing and expects that everyone will do it. It has been like this for my sisters who are years older than me to. They both left before 17. Now for all the adults out there with kids, do you think these arrangements are fair?