I had the same - some pissed up muppet ploughed into my car which was parked outside my house, the insurance company offered me bugger all and i had to fight like crazy to get a decent amount back - print off ads from autotrader of similar cars in that condition and millage as you mums and let them know that you'll be sending them across for a more reasonable settlement. No one asked them to write her car off so why should she be out of pocket?? (i gave them so much grief that it was my pride and joy that they allowed me to take parts off my car like wheels and performance bits before it was collected, virtually stripped the fooker by the time it was taken!!!)