I had a similar t-child-appearance - t warned me that his son would be coming to the office with his puppy to pick something up, and would i mind stepping out. I was like, if hes bringing the puppy, i wanna stay!

It was so long ago (altho towards the end of my therapy) that i dont really remember what happened, but i do remember it feeling like a Transactional Analysis Diagram! This person is related to that person, etc etc. Like i could see the relational brainwaves. I felt a little left out from their relationship, but i felt they both recognized my position, i.e., future stepmother to the boy, it could still happen! Plus, really tiny puppy, right?

It sounds very different from what happened with your t and her daughter. Your t was oblivious to her daughters intrusion on your shared space. Big boo-boo on her part. I dont understand why she didnt see that. Sorry for just stating the obvious, but wow.