Obviously, this may not be a possible option for you ... and I loathe to say this, but you should probably just leave.
There's no way to deal with the issue without making it 'you vs. her'. Even if they don't like her (and know she's a bitch), maybe she's too important to them at this point ... so you're going to be perceived as 'the problem'.
If she is as bad as you say she is, surely other people will take note of that, you may want to hand in your resignation and inform upper management of the reasons why. And then move on.
There's no way to deal with the issue without making it 'you vs. her'. Even if they don't like her (and know she's a bitch), maybe she's too important to them at this point ... so you're going to be perceived as 'the problem'.
If she is as bad as you say she is, surely other people will take note of that, you may want to hand in your resignation and inform upper management of the reasons why. And then move on.
I wish you well.