Trying to decide if I should ask my new T Not to discuss me with old T anymore.

Difficult decision, for sure. Would it be possible to negotiate with your T to leave discussions you have regarding your feelings about former T out of supervision? The way it is, your former T is a silent witness to your sessions; how can that not influence how you process your feelings about her? It wouldn't matter so much if you wouldn't have contact with her again, but in the face of intending to pursue a post therapy relationship, it's certainly awkward.

ETA: The more I think about it, the more this supervision seems a blurring of boundaries that is inappropriate. It's like she's guiding your therapy, but you don't get to be a participant with her. It puts your T in a proxy-T role. One of the benefits of supervision is supposed to be the objectivity the supervisor can bring to the conduct of a therapy. Your former T brings knowledge of you, but that same knowledge is at a cost of her objectivity. How can she supervise in any way other than how she did/would conduct the therapy with you?