A counsellor is trained specifically in talking work: a postgraduate diploma or a master's, plus supervised practice hours. Five of the six of us are counsellors.
A counselling psychologist has a psychology degree underneath that and a master's or doctorate on top, and can use formal psychological assessment. Marlene is one. It does not make her better at the talking part; it makes her differently trained.
A psychiatrist is a medical doctor who specialised in mental health, and is the only one of the three who can prescribe or adjust medication. None of us can, and anybody who tells you otherwise is not one.
For most of what people come here with, the training matters less than whether you can stand being in a room with the person. That is what the first session is for.