The owner of the property would be liable for a guest's injuries that occurred on the property.  The fact that the neighbor was wearing leg or neck braces before she was injured by falling out of the chair is irrelevant because there ia rule in law that a defendant is liable for a plaintiff's injuries despite the plaintiff's condition.It would be advisable for your parents as the property owners to refer this case to their homeowner's insurance company.The fact that the neighbor didn't seek medical treatment for five days will not bar her claim because sometimes injuries don't manifest themselves immediately.  Her claim may include medical bills, pain and suffering, and documentation of any wage loss.  Compensation for the medical bills is straight reimbursement. Compensation for wage loss is straight reimbursement. The medical reports will document the nature and extent of her injuries and will be used to determine  compensation for pain and suffering.  Compensation for pain and suffering is an amount in addition to the medical bills.If the case is settled with your parents' homeowner's insurance, NO lawsuit is filed.  If the case is NOT settled, the neighbor could file a lawsuit, but don't worry about it because if a lawsuit is filed, the homeowner's insurance company will provide you and your parents (the owners of the property) an attorney at no cost.  The insurance company will handle the case.