First of all, determine the labor contract relationship between your mother and the unit, which is the beginning of institutional work injury appraisal.
Secondly, the labor relationship between your mother and the company, if the company does not pay social insurance, is obviously illegal for your mother. May need to be at the back of the unit.
The third unit failed to pay social insurance, resulting in the responsibility of industrial accidents. To determine the degree of disability, you can compensate for personal injury and apply to the court for disability appraisal.
Don't worry, the unit should bear the responsibility, you can hire a lawyer, and the lawyer's fee can be claimed by the unit.
Blessing!