If you bring in an aesthetics practitioner one day a week, sooner or later you'll wonder how much you should be promoting them. Some owners put the practitioner on their website, mention them to every client and treat filling their diary as part of their own job. Others feel just as strongly that it's the practitioner's business, and getting busy is up to them. Both views are understandable, and the gap between them causes a lot of quiet resentment on both sides.
The right answer depends on how the arrangement works. If you take a percentage of what they earn, their busy diary is part of your income, so promoting them makes sense. If they pay a fixed room fee, there's less reason to do their marketing for them, although you still want that room earning and your clients well looked after. We'll work out where you stand, agree who is responsible for what, and get it written down before it turns into a falling-out.