Yes, you definitely did the right thing.
If she gets caught without vehicle tags and no insurance, then she will have to pay the consequences for her negligence.
Don’t let her guilt you into paying for any of it. Sometimes people step up to the plate when they have to face the consequences of their behavior. Not always, but, then, it happens more often than it does if someone else always bails them out and they never have to face their problems. She shouldn’t be driving, anyway, since there is the possibility that she is using drugs.