For all the lights to light up, could be a battery/alternator issue.
Although I agree with the refund, it equally could be something she has done, i.e put diesel in a petrol, damaged some parts.
I'd get a workshop to diagnose the issue before parting with any money. Explain to her you want an impartial party to look at it first. If its an easy fix, explain everything to her, pay for the fix and happy days. Work from there....