Sounds like a casual chit chat to me. I’d not read too much into it.

One might read it as she needs validation but it could just be random talk. You keep asking her a lot of questions asking for a lot of information and details so it’s only expected that she’d respond back in details. As about random talk about her tooth. You two don’t have much in common except you were in school as children so what else would she talk about. Sounds like pointless small talk to me.

I don’t fully understand you engaging in lengthy conversations with someone you said is a bully and someone you have no interest in seeing. This conversation sounds very unauthentic to me. If you dislike her and have very negative thoughts about her, why write these friendly messages asking her questions like you care about her. It’s s major contradiction.

I don’t see a need in a small talk with someone I dislike.