What can my family do for my mom? She is being mistreated putting it very mildly at her job of almost 25yrs.

She works 6 to 7 days a week. She goes 4 to 6 hrs and sometimes almost all day without being able to go to the bathroom. She has 14 students and no help in the classroom. She is the only teacher that does not get a break. She is required to teach higher classes on some subjects due to the teacher in that grade does not want to teach those subjects. My mom is physically going down hill. If something is not done our family is very concerned on what is going to happen to her.