For whatever this might be worth, I've been seeing my therapist for a couple years and I think he's blocked me on Facebook. I say that because I once saw his locked profile pic and then a week later it was gone, and now if I search and search I cant find anything, not even a locked profile. My therapist does some things, like hugs, emergency calls... just not Facebook (and I know he has one because he mentioned it). I don't think many do, it is just so personal it's the kind of thing that can really alter your image of someone. I guess what I'm saying is, wow cant believe she friended you at all! and I wouldn't take the unfriending bit to be personal. I would ask her if this means there's a chance you could friend her to stay in touch at the end of therapy?