My T doesn't talk about other clients, and I think if she did I wouldn't like it as I'd then start worrying if she was using me as an example to others!
However i do get curious, I wonder who else she sees, how their relationship is, is it better/worse than ours, am I her least enjoyable one etc.. and yes that makes jealousy rest its ugly head. I think for me the more I knew the worse I'd become with jealousy, my own thoughts and imagines are bad enough. So I hope she continues to tell me nothing!