Great minds! That thought just occured to me (in the shower, which is where I do my best thinking.) I don't recall her mentioning it.
Also, one of the girls used "levicorpus" on one of the death eaters at the ministry. That curse isn't mentioned until book 6 when Harry discovers it, so how did she know it...???
I think that’s the one James uses on Snape, but you are right- Harry doesn’t try it out until he uses it on Ron in HPB. I remember Lupin or Sirius saying that it was the “fashionable” charm to use when they were in school.
The other thing I thought was odd was that Umbridge blasts through the door of the room of requirement. How are they going to rectify that with Harry trying to get inside it in HBP? People who aren’t familiar with the books will probably just think, “Why doesn’t he just blast through like Umbridge did?”