I think it's okay. If the ads were in her office, then that tells me it was okay for clients to see. Speaking as someone who has publicly displayed art that I wouldn't want clients to see, I don't censor myself but I would never post anything about said art in my office. It sounds like your therapist was more open, and also that you honestly care about her boundaries. I hope she'll be fine with it (and think she will). If I were her, I would be touched by your honesty and caring about the boundaries.