Oh I forgot about Helya...yeah I guess she was a pretty main antagonist.
And yeah Jaina and Sylvanas are our big go-toes when it comes to female protagonists. Jaina was kind of a big deal in MoP too so yeah I guess I forgot that as well. They definitely had a big impact in the last patches of Wrath involving Arthas himself.
While Yrel has been a big help Alliance side...I dunno if I want to include her. It was kind of a self-contained story and we're unlikely to ever see her again. Although I actually liked her Joan of Arc kind of story. It wasn't told AMAZINGLY but it worked for me.