First ethical question , do you have other crew members? Is the cabin suitable for one to one sessions to allow a confidential environment.
If you are considering on-line counselling , I would recommend doing further training to equip yourself with the different aspects you do not require for face to face counselling such as secure email for contracting. Secure software (Zoom is not 100% secure). Procedures for reconnecting if a session is interrupted, insurance, payment methods etc.
Given a good wifi signal this should allow you to cruise and deal with clients.
As you mentioned I would start this off with discussing this at Supervision