There is that, but she gave me a written/signed letter saying that the payment was to be made in lieu of any insurance claim. If she did decide to change her mind further down the line, we'd both be in trouble as the evidence said it was her decision to no go through it.
I once had the wing of my wife's lease car dented by a van driver. I was covered through my own insurance only as third party (I only offered to collect it for her!) and despite trying to work with my insurer, her insurer and the van driver's insurer, and having gained a still from council CCTV showing the impact and positioning of the cars, none were interested. I of course declared that 'incident' for the next five years, so naturally saw an increased premium.
If a similar incident happens again, I'd prefer the non-insurance approach with a signed letter between both.