Verity will definitely fight and I love the idea of them being separated!
Felicity will run SO FAST I can't even.
Aud will fight and I'm very alright with her dying.
Ginny will fight and run the DA, getting people out and all. I'd sort of like there to be a moment where maybe she almost gets cursed from behind or something and Harry saves her and she snogs him. SORRY, SAM.
Gretchen will be no where near Hogwarts. Well, no, she'll probably be in Hogsmeade, having sex with Trev. But she will DEF not fight.