If she yells.. let her yell, don't yell back. Its hard for someone to have an argument by themself. By not yelling back... she will stop a LOT sooner. Try it... you will see I'm right. That's one way to defuse a situation where emotions are running high. Trust me...I have a temper myself....if anyone yells at me....my impulse is to yell back. But doing so most times would not be in my favor.