Most employees are employees "at will" in their employment. This means the employee can walk away from the job at any time. But this also means the employer can terminate the employment at any time as long as the action is non-discriminatory and can change the conditions under which work as long as no laws are violated. So, unfortunately, your relative even after 7 years of faithful service has no "right" to be re-hired.
THESE COMMENTS ARE NOT LEGAL ADVICE. They are provided for informational purposes only. Actual legal advice can only be provided after consultation by an attorney licensed in your jurisdiction. Answering this question does not create an attorney-client relationship or otherwise require further consultation.