OK - UK ex elder here - this is my twopennorth.
If she is prepared to "take this all the way" and is wanting to stay in the congo (and accept gossip and slander and all the snooty looks) then this is what she should do.
Go to the brother with her case in writing.
Bro. Rex Karz
Looneytune Cong of JW's
Fairyland
Dear Bro Karz
On Thursday last you insisted upon getting my car out of a tight spot in the kingdom hall car park. You damaged it (photo's enclosed) and the cost of repair is shown on three estimates from reputable repairers ranging from £600 to £750. I appreciate you were trying to help but the result is that I need my car fixing. According to my insurers I am not insured for this and neither are you.
Our verbal communication thus far has proved worrying to me in your reluctance to address this matter properly and I now reluctantly inform you that I expect you to pay me the sum of the repairs as soon as possible. If you have not agreed to this within seven days then I will apply the first stage of Matthew 18. Any refusal by you to follow the steps outlined in this bible-based procedure will result in my formally writing to the body of elders to enable them to suggest two witnesses who can ascertain the facts.
In turn, if I feel that I if am being "fobbed off", disrespected and/or treated in an unchristian manner over this matter then I will take it up with the circuit overseer or branch office.
I remain
Your loving sister in Jehovah's service (!)
Minnie Driver
(You may choose - in writing - to say that you will accept payment over say 6 months or even a year and you may agree that you were partly to blame - that's up to you - but start high I say)
Sadly I reckon sister will get taken for a ride because she will not square up to this elder.