Try to build positive feelings within ourself. Hatred can be pretty consuming and acidic to the soul.
Try moving your hatred to sympathy, then upgrade that feeling of sympathy to empathy. No matter how hard it is, try to show her some respect and see how she recipocrates. You must know that it is good enough for you, if she thinks it is not good enough for her, try not to think of her or decrease your interaction with her when possible, till you slowly build up a positive feelings towards her.
See what happens from there! Hope your relationship will improve. All the best!