It could be a stomach ulcer.. Its something you might want to check into, call the vet to get a well check done. Just know that weather or not she's has one. She shouldn't be acting out towards you.
There has to be respect weather or not she's hurting. You feed her, you clean her, you fix her boo boos. You deserve respect.
You should start teaching her manners. You don't need to show her your not a threat you need to show her that you are MOM and if she acts out there will be repercussions for her actions. Every time she Pins her ears at you tell her "No" make it loud and assertive warning.
Don't yell at her, she can hear the anger or fear in your voice just use a "Big voice." When she bits or bits at you.. (be it a nip or a bit) giver her a nice hard slap on the nose. Don't hit her, just a slap.. like how mom use to do when she would slap your hand when you would touch something you weren't suppose to.
Now for the food thing. Get a whip with a flag on the end of it. (Don't worry you WON'T be whipping her.) Take it with you into the stall with you when you go to feed her.
If your mare comes up on you push her back a few steps she is in your space, you aren't in hers. Make her move. She will come back, when she does stand by her side and take the whip in your hand then swish it in front of her.
(Separating her from her food with the swishing whip.) It will make a little swishing sound, it won't hurt her just get her to stop what she's doing. If that doesn't work.. just TAP her chest with the end of the whip and tell her to "back up" using your "big voice." Now a few other things you can do to get her to respect you is when your standing with her (it doent matter if your standing with her she's walking by you) you can bump her hip, making her back legs cross.
It will remind her of when she was a foal and her mother use to do it to her. Don't be pushy just let her know you can make her move. (Be careful doing this if she kicks.) Another thing, don't be afraid to get in her way, you can block, back her up, and make her go right and left.
You need to become her teacher, mother, and partner. She is not top mare when you two are together. You are top mare.
You are mom. Challenge her make her work. She won't hate you for it, she'll respect you.
And your bond will become stronger.
This "Nice Mare" has Chey's number! The mare WILL bite or kick eventually if she is not schooled. I am not one to bother a horse much when they are eating though some of them welcome it.
I would darned sure get that mare in a round pen and sort out her grooming crabs. I have known a few TBs like this and they do respond to a little constructive exercise. I am a dyed in the wool pragmatist.
I believe in what I have seen that WORKS. In this instance I know that constructive exercise, used properly, WILL work. I also have some experience with vets and chiropractors that want to "put you on a program."
Ulcers my hind foot!
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.