Something that I have yet to mention about knowing things about your Therapist is that I think that it can actually sometimes ease any feelings/transference that you may have (at least in my case). With my last Therapist I asked at the first session if she was married or not and when she told me that she was married that helped eased (but not totally eliminate) any feelings that I may have had, then a few sessions later I asked her if she had any children and she told me that she had a young daughter which helped ease feelings even more. So in other words sometimes knowing certain information can be very beatifically to me.