This will give her some background on meltdown:
http://www.angelfire.com/ky/touristinfo/tempertantrumwhy.html
You could suggest she read this book.
Asperger Syndrome and Difficult Moments: Practical solutions for tantrums, rage and meltdowns.
Brenda Smith Myles and Jack Southwick
I find meltdown very hard to deal with. Anger terrifies me.
Some strategies:
. Never try to discuss anything with an angry person.
. Some kids benefit from making a hidey hole that they can go to when they are angry. It isnt a punishment but a place to recover.
. You need to explain that if they have hurt anyone with words or actions, or done damage when angry, this will have to be discussed.
. If the kid wont go to the recovery place, it is best for everyone else to leave the room. I know this is hard and you worry that other people's things will be damaged. The angry person relies on this and you might just have to accept that some damage will be done. Then later a way has to be found for the angry person to make that up. This is really hard.
. When the kid is happy, you make a chart with them, identifying all the ways that his/her body tells them that meltdown is on its way. That is the time to go to the hidey hole, before trouble starts. The child can plan a signal so people know that he or she needs to get away and will talk later.
All this is so hard on your own though lilghostie. I can not always manage it and I have a daughter who really is scary when she is angry. I go outside and leave her to it. Later we pick the stuff up together and talk or figure out the consequences. My son has turned out a really gentle man, so I think it does work eventually.