Car accident

my daughter who is a minor, 17 yrs., was involved in an accident on private property, a shopping center, so no police report was taken. Someone had backed out from a parking slip and hit her. clearly the one backing out, so i thought, was 100% at fault. Their ins. co. had said they will take care of all damages to her car after interviewing both parties. 2 days later, they changed their mind after receiving the estimates of both vehicles. now they claim my daughter was speeding thru parking lot so she is 60% at fault. After seeing where accident occured, there is no way she was speeding, due to a stop sign several feet back from where accident occured. they paid out 40% of blue book, (our vehicles was a total loss according their ins. co., and our ins. was NO HELP, we did not have FULL coverage, only was the law required. Also their ins. co. i feel illegally interviewed my daughter, with her being a minor and all, shouldn't I have been present? I want to take them to small claims court to getttt the 60% at fault off my daughters record, and also get the remainding 60% of value of the vehicle. Do i sue the insurance co.? or the woman who hit her? by the way, the other driver was also a minor, 17 yrs., and was involved in a similiar accident not too long ago, so I've come to find out. Do I have a case?