What a brat. She knows what the right thing to do is, she's just not doing it because she doesn't feel like it.
I went through a phase with my horse were he didn't feel like going into the halter, and evaded it. It was a bloody nuisance, because - according to my trainer - the thing to do when this happens is to make that horse move. It's the old "make the wrong thing hard and the right thing easy" deal. So I'd go in with the halter, and he'd evade it, and then I'd have to drive him away, give him a chance to go in the halter, and when he didn't, I'd have to drive him away again. Keep his feet moving until he realized that things were a LOT harder if he refused than if he just did what I requested.
And this had to happen every. blasted. time. he evaded the halter. I wouldn't go in the paddock at all unless I had made certain that I'd have 20 minutes or so for our little paddock rodeo (since my horse can be pretty willful and stubborn, and it was taking 20 minutes or so of this before the penny dropped for him). This went on for what seemed an absurdly long time...maybe 6 weeks. But we got through it, and he went back to standing for the halter every single time.
So this is 100% a training issue - for you, on how to handle her, and for her, on why it's important to pay attention and follow your instructions.
Your mare can be grumpy all she wants on her own time, but she should not be expressing grumpiness at you. *You* should be able to expect that your horse will stand to be haltered AND that the mare will drop her head to receive the halter. These would be minimum expectations, IMO.
It is also something that it should be fairly easy to fix once you get the help of a trainer. They are VERY used to dealing with this kind of problem.