I also got the impression that Regina is actually traveling with them. There was that one pic of her holding what looked to be one of the blankets that would have been packed on a horse. It wasn’t necessarily a shot taken during actual filming, but why would Lana be holding it at all unless it was a prop for her in a scene, and why would she be holding it in a scene if she’s not part of their group? And she seems to have been there the whole time they were filming this stuff, which you wouldn’t think she would have been if she’d just briefly poofed in and out to drop a few threats on them. So I think that whatever’s going on, she’s cooperating with the rest of them, so maybe she’s not completely EQ.
Of course, she does seem to be dressed all EQ…but maybe she’s not? In my AU ponderings where I figured that she and Snow may not actually be enemies, I figured that perhaps she wasn’t the one who killed Leopold in this version. Perhaps she actually came to love him, and he her, and then he died, and having lost both him and Daniel, Regina took to just wearing black 24/7, like Queen Victoria did for the rest of her life after her husband died.