I would have to disagree with the suggestion that a "very nice Lady" should get a discount or allowed free admission because she's attended classes before. First, this is a private studio attached to the instructor's residence. Second, if she allows someone who is not a paying attendee to attend, she loses whatever tuition would have been earned for that seat. The OP suggested that "class size is small". The idea of someone attending a class with a new friend (and not paying for the class) is all wrong from the start and should be obvious to anyone. The instructor needs to make it very clear at the first class session that only paying students are admitted! I've taught vocational classes before (held at a local community college. As an instructor, you must remain in control, as the owner of the property where the class is held, the instructor is very much required to maintain control! As the instructor, I was responsible to the Community College as well, to make certain the amounts due to the college were paid, based on those who were ATTENDING the class. JMHO!!
Jeanette