Child's wheelchair

Katherine is my 11yr old daughter. She has Cerebral Palsy. She uses crutches for walking but needs a wheelchair for long distances. The wheelchair pictured has lasted her 6 yrs and now she needs a new one. We've had a quote for $5500 but as she is a New Zealander living in Australia, she is not eligible for MASS subsidy or any other concessions meaning we need to pay the full amount. My husband had a brain tumour removed 15 months ago and has not made a full recovery, meaning he has been unable to return to work, and I now care for him, Katherine and our 2 other children. I cannot get a carers allowance because they are both NZ citizens, and not considered permanent residents despite living here for 7 yrs. I am an Australian Citizen but this does not help the status of my family. We have tried approaching Variety for assistance in getting this wheelchair but we have not been successful. Katherine's chair is too small for her, and she now desperately needs a new chair. She is a very bright girl, who excels at school, and next year she will start High School. As fatigue will be an issue for her, a whelchair is needed to alleviate this. Any help to reach our target is appreciated.