Help Trouble with school has to do with weed..PLEASE HELP?

So the other day at school i was outta class going to the bathroom when a girl ask for a water bottle of mine so i gave her my water bottle and she happen to be going to the same bathroom as me and she did he stuff and started lighting up her weed so the teacher walked in i happen to be there they caught the girl with over 2 grams of weed in her bag.I got drugged tested twice both came out negative and i still got suspended so this girl is going to court now and im really stressing out cause she want to try to put it on me is there any way i can get in trouble with he law? she also came back to school and she wants to start crap whats the best i can do to avoid her?