How do you deal with a friend that has anger issues?

So I have this friend who is very spoiled and always complains that certain things aren't fair. Then when we think she was outside intstead of in the lunch room we go outside. So when she says we ditched her when we didnt even see her she gets all mad at us and starts cussing and saying were mean and horrible friends and almost every time we do that she says you guys should know better. We're not her little puppies or two years old. My point is how do we tell her to stop?