I am a law school graduate. What I offfer is mere information, not to be construed as forming an attorney client relationship.
I found a couple of things at the freeadvice.com homepage under EMPLOYMENT LAW that may help your daughter in law's situation:
MY WORKING CONDITIONS WERE INTOLERABLE SO I QUIT. CAN I CHALLENGE MY JOB LOSS AS IF I WAS FIRED?
Probably. Most states recognize "constructive termination" of employment and treat it similarly to an actual firing. For example, if the employer reduces your wages from $12 per hour to $6 per hour, switches your day hours to the moonlight shifts, and changes your position from secretary to stevedore, that would clearly be a constructive termination.
An employee in a state that recognizes constructive wrongful termination does not have to be fired in order to have the ability to sue an employer for intolerable working conditions. If an employee can prove that an employer created intolerable working conditions in an effort to get the employee to quit, and these conditions were known by the employer, or intentionally created by the employer, then the employee may pursue a constructive wrongful termination action.
The remedies available in a successful constructive wrongful termination action are similar to those in a suit due to actual wrongful termination.
DOES FEDERAL LAW PROHIBIT CERTAIN EMPLOYMENT PRACTICES?
Yes. Some of the more common federal laws regulating employment practices include the following:
Title VII of the Civil Rights Act prohibits discrimination in employment based on race, color, religion, sex or national origin.
The Employee Retirement Income Security Act (ERISA) regulates company pension benefit plans.
The Occupational Safety and Health Act regulates workplace safety and health conditions.
The Family and Medical Leave Act requires an employer to allow up to 12 weeks of unpaid leave each year for certain family matters (like the birth of a child).
The Age Discrimination in Employment Act prohibits employment discrimination based on age (this applies to employees who are forty years old or older, whose employers have twenty or more employees).
The Americans with Disabilities Act prohibits discrimination against persons with physical and mental disabilities (this applies to employers with fifteen or more employees, and protects those who meet the "requisite skill, experience, education and other job related requirements" subject to "reasonable accommodations" being made for the disability).
The Fair Labor Standards Act establishes minimum wage and overtime standards, as well as child labor rules (this applies to employers with two or more employees engaged in interstate commerce).
The Equal Pay Act requires employers to pay employees who perform substantially equivalent work the same wage regardless of the whether the employee is male or female (although pay differences based on seniority, merit or piece rate are permissible).
The Pregnancy Discrimination Act prohibits discrimination on the basis of pregnancy, childbirth, and related medical conditions.
The Immigration Reform and Control Act prohibits the employment of aliens (non-U.S. citizens without proper documentation of the legal right to work in the U.S.).