I know I would be beyond freaked out if I went to therapy and the lady told me she drove/walked by my apartment. I live in a major "square" across from a landmark in a city.. She knows where I live (has my address).. But that would be my reaction. Some would have the opposite or no reaction.

I do not believe human curiosity is a pathology; I just personally do not need to hear about it. If this were the case, I believe the lady knows me well enough not to tell me she was "in the neighborhood." If you do not know for sure what her reaction would be, it may be a disaster for the therapeutic relationship, if you care about it -- as some have mentioned the "emotional connection" (I don't care for this, but I get why a lot of people do).

I am understanding you may feel guilty over this because you are desiring "more" from your therapist that you are not getting, perhaps? Do you feel guilty because this action feels "out of turn" from your usual self? Maybe instead of talking about the actual action, talk with her about the metaphorical action -- Talk about the feelings of needing more connection instead of what you (innocently, I believe), did. You could ask "feeler" questions about her house? Get a gist on what her reaction would be. "Blah blah I was working in my garage and blah blah.. do you have a garage?" I don't think there is really a solid answer on this. You can always discuss being in turmoil over your connection without actually mentioning you did a drive-by if the potential to do so would hurt your relationship. Good luck.