I would discuss it with your counselor, your thoughts and worries. There is no hard and fast "law" that you could convict a therapist/counselor on if they told something you thought was private. I would make sure my counselor and I were on the same page as far as what is private and what she might tell another and how/why/in what conditions, etc.

I believe clients can be talked about with others, without identifying details, just as we might discuss people we know at work or socially with others if their thoughts/stories illustrated a point we were making or a difficulty we were having. Ts are going to think, "Oh, that reminds me of Perna" when others say/do something, just as we are, and there is always the, "I know someone who. . .".

Ts are probably less likely to blurt something out than the rest of us but we can never know which is why it is good to really talk with one's therapist and get a good sense of the sort of person they are. If I had a really open therapist who revealed a goodly amount about themselves or other clients to me, and that bothered me (it does not Me), I think I would be a bit more discreet about how/what I told them as they may be equally as likely to share about us in the "I know someone who. . ." conversations of life.