If she ends up with several thousand dollars in vet bills, she should sue. Sue the driver, sue the driver’s insurance company. That’s what small claims court is for. The judge would award her the vet bill amount.
Though this sort of awfulness is yet another reason to have veterinary insurance.
Conceivably, she could sue for much more than vet bills. After all, the agreement with the insurance company is between them and the driver. She’s not bound by it.