Can an employer ask a salaried employee not to come in one day to avoid paying a days wages?

My cousin turned in her two week notice and her employer is asking her to miss some days of work in order to not give her a full paycheck at the end of the two weeks. We live in an at will State but I couldn't find information to clarify if it is legal or not to withhold a days wages if the Employer requested it for mere savings on his part. There are no layoffs or financial issues with his company since it is only him and my cousin who work in the office.