With a fear-aggression dog - one thing I would do would be to teach her that new things aren't so scary. Start carrying treats with you at all times. Let's just say that she gets scared while going on walks and when she encounters another dog.

So, you start taking her for walks more often and treat her when she behaves. The second another dog steps into the picture, you get her attention and treat her when she does. Eventually she'll put two and two together that good things happen around other dogs (just as an example).

I prefer working with more skittish animals because it is such a joy when they finally come around and the little light clicks on.

Of course there are other tricks and methods to helping an animal overcome fear and this is just the method I have used. Others may have other opinions