Travel allowances for personal vehicles.

Hey peoples, just have a few questions and figure this is probably the place to ask.

My aunty works as a support worker for a Māori healthcare provider, as you can imagine the pay is pretty low (~$26/h) and she travels from job to job in her personal vehicle. She averages about 9 clients a day so obviously fuel and vehicle maintenance is higher than that of someone working in a set place or office. In my line of work if I was using my personal vehicle for work purposes I'd be reimbursed 79c/km but apparently aunty is only entitled to payment if she travels longer than 17km between jobs. Does this seem right? How should she approach her employer about this?