I'm not sure if she's old enough for this, but her language sounds fairly good so it might work...

I tell DS I can't understand him when he's screaming/whining/yelling and ask him to ask me nicely. More often than not he stops and asks nicely, if he's needing an outlet he won't he just screams so I hold him til he calms.

Sometimes they just need to have a yell and release some frustration. It must be very frustrating not being able to communicate how they want to.