My advice would be to simply ignore the drama and chow down on work. If your manager starts giving you a hard time for that, you start documenting about her behaviour towards you...
That way, it can show that you're interested in the work and that you're able to fight through office drama like this. It can also get you "the long end" in any discussion - you're demonstrably trying to do work, while she and that part of the team are actively trying to sabotage you.
Don't get directly involved in the fight unless you really, really have to. Concentrate on work and keep delivering product - at some point she'll end up either sabotaging herself (at which point you drop the "bombshell" of documentation of incidents at HR) or she'll stop. It sounds like she's made it abundantly clear that she doesn't want to be there.
In a situation like this, you stay cool, you stay mature and you stay civil and professional. You do not play ball or feed the troll - you do what you're hired to do and you do it well. If she starts cutting you off from more work, you already have opportunity to gather evidence.
Patience is key - i've had this way of handling office drama help in the past. It can turn into an opportunity if you play it right. And it's its own reward to be able to sit back and shoot their career in the foot :)
Remember - it's not your job to fix the problem... unless "manager" is in your title, it's not your fight to join unless it's directed at you or unless you're certain that you can "win"