Based on the information provided, I don't believe it is so clear that she is a "independent contractor." She may in fact be a part-time employee, who is still covered under the employer's workers' compensation. Each case is fact specific, and NOT determinative simply how the employer labels the position. As you pointed out in your additional information provided, it appears that the "tools and materials" and schedule are provided by the employer, which are generally the most siginficant factors leaning in the direction that she is an employee rather than an independent contractor, regardless of how the employer classifies her. Therefore, she would be covered under workers' compensation. It is a legal issue, and she needs the assistance of an experienced and qualified workers' compensation attorney.
The attorney should file a claim for workers' compensation benefits on her behalf, and serve it on the employer's workers' compensation insurance company. Your girlfriend does not even need to discuss this matter further with her employer. I don't recommend it, as this legal issue only develops into an unecessarily adversarial situation. The issues then become deferred to her attorney and the workers' compensation insurance company. If your girlfriend's injury is covered under workers' compensation, your self-procured expenses on medical treatment would be reimbursed. She would be entitled to appropriate medical treatment, temporary disability, permanent disability, and future medical care benefits, if applicable.
Please feel free to contact me if you have further questions.
There is a possibility that your girlfriend was misclassified as an independent contractor, that she is actually an employee, and that the case would have to be handled through workers' compensation. However, your girlfriend's case is not nearly that complicated. If she was classified as an independent contractor, then she would just have an ordinary personal injury case (i.e. a suit for negligence). The value of the case would depend on the severity of the injury. You should consult a personal injury attorney.
It is not uncommon for someone who thinks they are an independent contractor to really be an employee. Your girlfriend should tell the school she wants to make a workers' comp claim for the injury. They may object but they are required to give her a claim form. There are very specific tests used to determine employee vs. independent contractor status.
She should contact a workers' comp attorney to discuss this. There are plenty of good ones in L.A. Find a good one here at www.avvo.com or at www.caaa.org. CAAA is the association for attorneys here in California who represent injured workrs. Or she can call me for a referral.
If she really was an independent contractor and not an employee, did she have health insurance?