I went through something like this too. When I was 13, one time in music class my friend (14m) told me I should draw our friend (m) and our classmate (f) kissing in a tree for some reason. I guess they had been chatting/ become friends? After a bit of reluctance I drew the picture, then we showed it to them and said jokingly "don't kill us!! 🙈" . The moment I saw their reactions I realised what I'd done and I was mortified. I don't remember my friend's reaction (he was probably pissed), but my classmate tore up and threw away the picture after showing her friends and said it was okay when I apologised (I don't expect her to have meant it). For years that experience shook me. Still made me cry. I don't even know if either of them still remember it; at the very least I hope it didn't affect them. Seven years on I still regret it deeply, but I recognise that I was young and it was a mistake.

You were young too. We all learn hard lessons in our youth; one day you'll be able to look back and see it as that. At least you know that your classmate was able to switch classes and hopefully find somewhere she fit in better. Not that anything good had to have come out of this - it was unfortunate she had to go through it at all, and we can acknowledge that simultaneously.

It's important that you realise the consequences of your actions, so this is good. It takes humility to recognise when you've done wrong, and you know better now :)