Thank you all for some good advice. I will incorporate a combination of your replies when I talk with her.
For clarification, I do not have a shop and do not sell anything. I am a longtime quilter and I enjoy helping others learn quilting and the joy of it. I am retired and it's more of a hobby than a business. I spend a lot of time preparing for the classes and I like helping, but I don't like feeling used or taken advantage of.
The lady in question has been quilting for many years and is a professional longarm quilter. Maybe I misunderstood her and she is planning on taking the class (and paying for it), but the way she said it she sure sounded like she was coming "with" her friend and not as a class member. It was not only what she said but how she said it.
Anyway, I am going to talk to her, as I knew I would. I appreciate all your suggestions.