Toomanytoomany
I am a youth worker and have worked with many young people like this.
There is a program down there call Youth Insearch that I use to work for that has a great reputation for working with young people like this. PM me and I can give you the details. They can also refer to other services where needed.

Like it was also suggested, maybe finishing school in an environment like TAFE??? Is there anything she wants to do when she finishes...maybe an apprenticeship/traineeship????

I know its hard (i used to be one of these types of kids) but it does work out in the end. Shes at a stage where shes probably feeling like shes not yet and adult and not a child anymore.

It sounds to mee like you are doing a great job and doing everything that you can do. Peserve, but also make sure you look after yourself. I'm sending you lots and lots of hugs. xxx