This could be pain still, she could be anticipating pain. I have a number of suggestions:
1) Get a vet to give her a Full check up! Including a soundness test. This could have something to do with her heat cycle, perhaps you should look into raspberry leaves or some equal alternative if it IS connected to that - talk to your vet.
2) Yes this is a SEVERE lack of respect, and regardless of the cause she Can Not get away with that. If she kicks in your direction on the lunge go right after her, make her go faster every time she kicks, let her slow down when she's being respectful. Now having said this I need to tell you - cantering on the lunge is NOT easy for a horse! Cantering IMO should only be done once, maybe twice around. I honestly don't see ANY reason to need to ever make a horse canter on the lunge aside from teaching a new rider the feel of a canter, which I assume you aren't doing. If your intention is to 'tire her out' before you ride her this is a poor way of doing it. Cantering is Very difficult on a horse's stifles and hocks, especially on tight circles! Personally I only ever make my horse canter on the lunge if it's to reprimand a horrible act she commits while trotting, and only enough to make my point - this has not happened yet, but it's an option I'm open to. Even if she's totally sound she may not be balanced enough. If you are repeated asking her to do something that hurts her or frightens her (feeling off balance can be quite scarey) she will try very hard, then when she can't do it she will finally try to let you know that this is too hard for her.
As for kicking at you while catching her I would round pen this horse, make her WANT to come to you. In the mean time carry a stick with you for self defense. You want to make her work more by having to be away from you than with you. So if she's going to insist on running away keep her running- only where you want, herd her around keep her going and going until she decides that sucks and it's easier to just go with you.
3) She clearly does not want to be with you. Could it be that every time you fetch her from the field you make her work? You make her do things that are unpleasant for her - so why would she willingly ever go to you? Perhaps next time you catch her you just take her out and let her graze? Maybe take her in and just groom her, itching ALL her favorite itchy spots, then let her go back out. Switch it up. If 50% of the time you do something wonderful for her and 50% you make her work, she's going to be more likely to take that gamble.
Practice ALL the typical ground work and yielding skills that all horses should know - if you don't know them I'd be happy to go into those details. If you don't have a round pen make one by roping off the corners of your most square paddock and round pen the horse. Spend time letting your horse enjoy you, not just the other way around.
You clearly love your horse, but it has to be mutual - you clearly respect your horse, but it HAS to be mutual. It's your job as her leader to make this happen.
Good luck, if you need any clarification, just ask.
ETA: I agree, get a trainer to help you - but I'm very much for do-it-yourself - but I think if you found someone more knowledgeable to come and just show you how that would be easier for you than advice given on the internet. I ALSO agree that you should not handle this horse unless someone is there to call if need occurs - but I say the same thing for most people with most horses.
ETA x2: ALL horses are potentially dangerous, even if it's an accident or they got scared - they can all be dangerous. Your horse has shown signs of severe lack of respect/trust and has acted out aggressively. This makes her a dangerous horse. But this does not make her unfixable. You Can Do This. You may need help - that's not bad, you've come this far in asking for help, I'm sure you can take it just one more little step to get some in-person help.
Last edited by PunksTank; 08-29-2012 at 10:05 PM.