Two things come to mind. First, your 13 year old needs to ignore her and stop giving her the satisfaction of a response, stay away from her, send the 10 year old to a separate room, etc.. That seems to be what she is looking for. Second, you need to find out what is going on with her. Talk to her and find out what's going on that she feels the need to make someone else miserable. Misery loves company.
Then try implementing a new rule. Home is a safe place, no being mean to each other. That's my rule. It's not iron clad and it certainly doesn't stop all the bickering and fighting. We should have room to disagree, it's different than being mean. I believe that the home should be a place where everyone can relax from the pressures of the outside world. We have plenty of people to be nasty to us, our home should be safe and comforting. Hope this helps.
at 5:46 PM on Sep. 15, 2010