Yes, you're in control of what happens to your vehicle, not anyone else. You have the entitlement to have your car repaired wherever you wish. If her insurer is going to authorise repairs directly, speak to the bodyshop manager, and have a contract in place where you advise that you are contracting with them to repair your car. Insist that they act on your behalf when discussing cost and repair methods with the insurer.

Insurers try to reduce the cost of the repair and do it for as little as possible, make the bodyshop aware that you do not give them authority to negotiate away your financial loss (it is your claim, no one else's) and your entitlement is here: www.honestjohn.co.uk/insurance/coles-v-hetherton-w.../

Doing this protects you, should you not be happy with the repairs. When an "at fault" insurer authorises repairs directly, you have no "entitlements" to complain to them or the Ombudsman if you have a complaint. I would always suggest going through an accident management company/solicitor or your insurer so that you have all the bases covered should things not go well and you need to complain. Should you deal with the "at fault" insurer directly, make sure you have that written contract in place with the repairer. That way, you're protected on top of your consumer rights.