John and Joan had been married for 20 years before John died in 2012. Joan and her son Marley, age 21, continued to live at home in years 2012 2015. Marley worked part-time (earning $5,000 in each of the four years). He also attended college on a part-time basis. Joan provided more than 50% of Marleys support in each year. What is Joans filing status for 2012, 2013, 2014, and 2015? Would Joans filing status change if Marley attended school full-time rather than part-time? If so, how?