Aww.. She is protecting her favorite flock member. I had this problem with Nilah attacking others on occasion. I read that in the wild, amazons have a mate for life, and although they would go off to forage for food, they always returned and would just stay nearby their chosen mate and hang out preening, not really interacting, just wanting to be together. After I read that, I understood her behaviour a bit more, she was protecting me from others......I allowed her to be with me and talked , including her in my daily activities and cuddled more with her, and she has calmed down. But she does like to be with me...