I read your other post before I read this one and I wanted to make sure and let you know that punishing would be a mistake at this point because the tantrums are stemming from abuse and punishing her may send the message that she deserves it. You need to get her to a child counselor and get her out of that school and as hard as it is to be depressed and have to deal with a screaming child, you just have to keep in mind that its about her and making sure she is safe. If a child starts acting in a pacular way there is usually a pretty good reason why. I really want to stress that while I am not against giving a swat when needed, in this situation that furthers her concept of abuse and she may get the message that she deserves to be hit. Its good that you have figured out why she is acting out, but you need to seek a therapist that can help you in how to handle her outbursts because they are a cry for help and not meant to be misbehavior.