Yeah she's honestly just a noisy kid. Is what she doing good? No. But it's just not worth hating a character for. It's not being done out if hatred or bad intentions. She's trying to help someone she cares about not realizing what she's doing isn't right. That's all. It'll be ok as long as the seme has an honest convo with her.
She would be between 18-22 assuming she didnt take a break. I generally think of college kids as kids. Theyre legally adults (I think after 19 in SK) but they're still young enough in experience to be normally considered kids.
What she's doing is totally something a nosy kid would do. So I'm not even suprised. The way you handle this sort of situation IRL is by calmly talking. She'll listen because she's not trying to cause any harm.
Everyone needs to relax its all good. Stop hating on the poor girl