my wife knows the first name of my T, but even I don't know her last name other than what I can butcher from hearing it on her vm message. she knows that this T is at the same office as a previous T, but wouldn't exactly know how to contact her unless she went through my phone to find her contact info. My mom knows I go to a T, and I mention her first name, but she would not know how to contact T. Both my mom and wife have had contact with previous T's as it was helpful at the time. Nothing like that is set up with this T though.
A few select friends know I go to T, but no idea who or where or for what. Some really close friends know I have had really severe depression with suicide attempts, so they assume I go for things related to that. Only my wife and mom know there's more to it, and no one knows all of it, not even T.
my dogs know it all, but I'm pretty sure they are neither telling nor going to attempt to contact T, lol.

I do not recommend T's, though may point people in the general direction of a competant T I know and may work well with them. I worked in mental health for many years, so it's not really a tabboo thing to talk about in my circles.