I was at the GP a few years ago, and as I left the consultation room, the next name was called out. Lo and behold, it was my secondary school bully. Hadn't seen her since 1992.
At the time of the bullying in the early 90s, it all came to a head at one point before a class. She was massively called out on it, and an assembly was put on, plus an anti-bullying initiative, and she did apologise to me.
It's funny that she got to me so much (she was in my class) as two years earlier when I had just started secondary school, some of my sister's classmates tried to bully me and I had no problems telling them to fuck off, and asking who the hell they thought they were. But the girl in my class really got to me.
Anyway, at the GP, she was morbidly obese, looked really unwell, and when she stood up, she could barely walk. She just looked so old and so unwell, I was shocked. And no I took no pleasure in that. I have my own health issues. I had zero interest in talking to her or thinking about her past seeing her there.
Honestly I would not make contact with this person. You are not going to get what you want out of it. What if she turns around and laughs at you? Will you go back to square one?