What do you mean by "pick on her a bit?" Pigs are herd animals, and I doubt she'd be happier alone. But she might be happier with just one other pig rather than a whole herd. On the other hand, if they're not just outright torturing her, she might be ok where she is.
It does sound like she's deaf. Can she see? What color is she?
The head tilt may be neurological,, or it may just be left over from an ear infection. There's really no way to know.