Make sure you're a Good Thing for your horse. Positively reinforce(reward) her for being with you, with treats, scratchies, games, whatever she really likes. Spend time with her just hanging out. Do much more Good Stuff with her than Bad(in her eyes) and make sure whenever you 'catch' her, it's all good.
Make the Wrong Thing difficult & the Right Thing easy. To make it easier for you, start off in a small paddock. Call her, your bodylanguage relaxed & inviting. If/when she ignores you or moves away, then focus strongly on her hind quarters(that you want facing away from you), use energetic bodylanguage & start to go after her. Whenever she's moving away from you, keep the pressure on.
Watch her body language closely, for the smallest signs she's thinking of stopping or approaching you(or to begin with, just interested to know what on earth you're up to!). When she points her ear at you, hesitates, turns to look at you, whatever, stop in your tracks, relax your bodylanguage & turn away(maybe even walk away). If she approaches you then, great! Just keep relaxed & looking away & let her come. If she doesn't, after a few seconds, turn & invite her to you again. Repeat the process until she learns that all she has to do is give you her attention to make you stop chasing her. Repeat the process until she learns to come to you.
When you get her to approach you, make sure you have an Extra Good Reward(pieces of carrot, perhaps) to give her, then walk away. Repeat the process until this is reliable before giving her a neck rub or such when she comes. Use the halter to rub her neck. Use approach & retreat if she's nervous about it. When she first allows you to put it around her neck, give her an Extra Good Treat and walk away. Repeat this process until she's reliably confident about approaching you & putting her halter on. Once haltered & caught, make sure you only do nice stuff with her for a few minutes at least every time.