Very good advice awifey
OP, when I said "jealous" I didn't mean it in the sense that you'd like to do what she does, I meant it in the sense that she's getting some special treatment for no obvious reason, whilst you probably work twice as hard and you are getting nothing out of it, in comparison. More to do with the fact she's getting away with things.
As others have said, there might be part of the story you don't know but bosses do. I totally get why you might be resentful, I think we've all experience that to some extent at some point. Especially when you are doing all the work and someone gets credit or doesn't get told off for not doing as much. I really get it. But having been there, I can see that getting so frustrated only affected my health and wellbeing, I was miserable going to work and this other person still did the same and was not affected at all. When I complained, it was seen as me having some kind of obsession against this other woman and it fired back on me. My complaints were always seen as me trying to get this woman in trouble, instead of me highlighting issues. At the end I was seen as a person who could not work well in teams and had problems finding the positives, so when promotions came I was passed over because I didn't have the right skill for the new management styles. I learnt from it, but I remember the times as very stressful.
My DH had exactly the same twice before in two different places with opposite results, in one he was seen as the moaner and soon singled out, in the other one he was seen as the harbinger of truth and the person took redundancy. But it all comes down to the bosses, HR and the procedures in place. Plus all other things that you might not know. She might have some mental health problem you are not aware of but HR is, maybe anxiety, maybe bipolar disorder, maybe diagnosed OCD, and they are dealing with it in the appropriate way or keeping a record of all this (if not a health issue) to bring a detail log when / if she's fired. Maybe they want to wait until after school, to see if it improves.
In any case, you've reported it, leave it now in their hands. They are aware. If you continue to bring complains, it will only look bad on you. And through the years I have always seen this kind of people been put in place in one way or another, eventually. Sometimes it's when redundancies are being made, sometimes they get new job descriptions that are not compatible with what they were doing, sometimes they think what they get away with is normal and they move company only to be faced with a different truth. But she will eventually be put in place. And your hard work will be eventually rewarded too.
Drop the axe! ;)