sw628, your old T is the one who must follow your boundary, not vice versa. If you welcome contact with her, greet her and she will respond. If you don't wish to acknowledge her, you don't have to--she will follow suit.

If it is a source of anxiety, I think ECHOES had a great suggestion--call your old T in advance and let her know you'll be there and what to expect.

It sounds like you left your old T on good terms, just because she was having a baby, not because you didn't like her. So do you know why you wouldn't want to see her at this meeting? Do you think it might make you wistful for the days when you were seeing her? If she is back from maternity leave, there might be the possibility to go back to having her be your regular T, if that is what you want.

Ethically, they can't talk about you unless they ask your permission and you sign a release form.