That would creep me out some too. However, I suspect that you could find a T that is willing to work with you without treating you differently because of your sister. My ex-boyfriend and I use the same agency. I sometimes wonder if his T and Pdoc ever talks to my T. I don't think I have ever named him in session (probably for this reason). But, the idea is kind of creepy in an odd sort of way even though it doesn't effect his time with T/Pdoc or my time with my T.