Hourly Pay

My wife is an hourly employee at her office. She is required to attend monthly staff meetings during her unpaid lunch break. She also has to go in a few Saturdays during the year to check the mail and do other paperwork. However, the office is closed on weekends and she is never paid for her work on weekends. At times, she is even required to bring training material home to study. She gets paid for none of this. Her office is closed the last Friday of each month, but all the employees are paid for that day. The office manager says this makes up for the unpaid hours she puts in. Is this true, or is something illegal going on here?