That is kind of weird. It wouldn't work for me either...in fact I wouldn't likely have gone to a second session, much less a third. You need to have a good fit between the two of you. I wouldn't blame you if you didn't just find someone else. However, for me I find it very empowering to be able to tell therapists directly what does and doesn't work for me. Sometimes I tell them face to face, but usually only if I want to salvage the relationship. In this case I would probably call and tell her on the phone call why you want to cancel your session with her and why you are quitting, that way you don't get charged for another session.