I have had a hand reared foal and until I read this thread I thought I just had one of those difficult foals. Now looking back I can see she attacked other people because she was jealous of them being near me, and protective of me. She grew into a fantastic 16 hh mare, but over her life three vets said I should have her pts as a dangerous horse. She was well behaved with me or my son, but really violently lashed out at anyone else. We had hand fed her together, with my young son helping me. She also seemed to be very 'human' she had expressions, moved her ears and pulled faces more than any of my other horses lol. She really was a character.

You need to stop her behaviour now. Do you use any natural horsemanship? I remember we tried join-up and the effect was catastrophic, she could not understand the change in me sending her away and the whole situation turned nasty, she threw a temper tantrum!, So be aware of that. Its one thing mimicking a herd or elder mare's posture and sending the foal out but if the foal does not know or hasn't experienced herd behavious then it is the wrong stance to take, and can confuse or do damge to your relationship rather than enforce it.

(By the way in the end I very sadly lost her through copd complications not her behaviour)