Yes,  a company may make a job untenable or undesirable, including by cutting hours (even all the way to zero) in hopes that an employee will quit. Remember: all employment is "employment at will" in this country--there is no right to a job, no guaranty of work or hours, and also no guaranty of fair or reasonable treatment. Your job is whatever your employer makes it, and if you don't want to work under those conditions, your recourse is to quit and seek other employment.That said, if they do cut her hours to zero, they will have effectively fired her, even if they don't want to call it a termination, and she should be eligible for unmployment benefits.