I found this amusing, that Lynn is saying that she has advised others. Yes, she has advised us in general postings to everyone about how things should be done. She has, however, complained that no one has come to her to be mentored, even though there's an art school in the area.
I read Stephen King's "On Writing," on this very topic. He would go for continuing to work for free for the Laundry List (or whatever that newsletter is called), while writing for pay for other publications. Getting published is the name of the game. If you don't want to continue doing it for free, discus it like an adult, or just quit.
Maybe I'm not clear on the concept, but isn't a "column" a regular feature, like how Joyce Maynard used to post updates on her suburban life every Saturday, and an "article" a single story? Or is it different in Canada?
As for mentoring vs. teaching art. Mentors do it for free. And there needs to be a friendly and professional relationship. If she dropped any hints to the school about being available to mentor, it probably had a price list enclosed. But I think that due to her strip being based on real life, that everyone knew not to bug her, and to stay away from the incompetent dentist, too. What relationship she may have had with the art school, we really don't know.