Hello @Poppy4105 ,
Welcome to these discussion boards. It's such a good group of people here and I hope that you find the supportive community you're looking for.
I need to acknowledge that I am not from Australia and I'm not familiar with Centrelink payments. I did a little bit of reading about it, but certainly do not understand the nuances of it.
Also, my children are younger by just a little bit so I'm not yet familiar with parenting children at an age where it becomes even more important to help them achieve skills for independence (whatever version of independence might mean for her).
From the start, I want to acknowledge that you mentioned you are parenting a child with health concerns. I don't know what that means, nor do you need to tell us; but, I know that ‘health issues’ can mean a whole spectrum of challenges, and I imagine that this may have had an impact on you in some way (little or small, in the past or in the present). The fact that you are here, asking questions about what you think is fair for her and what is reasonable for her, is testament to the fact that you want to do right by her.
I know it's hard to predict, but do you expect the support payments to be long term or short term? Do you anticipate her living with you for quite a while? Does her health situation preclude her from understanding or taking part in financial decision making? Is your daughter currently making sound decisions about her financial situation? (trust me, I need to work on making ‘sound financial decisions’, too--I mean, is she making risky choices about her finances in terms of substances or gambling or shopping or...).
As @Janine-RO mentions, it might be helpful for your daughter to understand and take part in budgeting and financial literacy skills. This income support--if it's anything similar to the country in which I live--can be less than adequate, and it may be important (depending on your daughter's situation) for her to get a realistic sense of what these supports can cover.
As wishy-washy as my answer seems, I think the answer to your question depends so much on where your daughter is in life right now.
For example, is she attending school? Growing up, the rule in my family and in my husband's family was that we would not have to contribute to household expenses if we were in school or training--in other words, if we were taking 'active steps' towards investing in our future, we didn't have to pay. For some, going to school might mean that the child is not expected to contribute to household expenses.
At the same time, we know life hands us big curve balls, and there are times when school or work are just not possible for a variety of reasons. In those cases, 'active steps towards investing in their own futures' might mean regular, consistent, and ongoing counselling. Perhaps, for some, that might be the criteria for living ‘rent free’.
And, for others, having our child within a stable environment might be the goal and contribution to household expenses might be the lesser goal. For example, my teenager went through a very risky stage and was running away and participating in very risky activities. The goal for us was to have her return and stay in the family home (again, she was younger at the time, and I’m not sure what I would do if she were 19 and doing the same).
For some, contributing to household expenses can be considered 'forced savings'. Once I started earning money and was still living in my family home, I contributed to rent, food, and so on. My parents didn't tell me at the time, but they kept the money and put it aside. Then, when I moved out, this money became a bit of a 'nest egg' for me. My parents were in the financial situation where they could do this and, ideally, I should have been able to save money for myself. But, they knew me, and anticipated that I might not have been able to save as much as I would have liked.
And, of course, it also depends on your own financial situation. Perhaps you’re in a tighter situation where it is difficult to shoulder your 19 year old’s expenses. That might come into play, as well, and that’s a very reasonable consideration.
I know this answer is all over the place, @Poppy4105 !
I hope you keep us updated.
, @Dadof4kids , @sidneysdad , @compassion , @Faob_1 
