Remember yo, little friend, you can either overwhelm her in imposing manner. The worst case is not being beaten, but being called a coward by others.
Also, don't fight first. If you really fight, remember to fight in the school or in a place with electronic eyes (with monitoring), and then it's self-defense. Remember, don't mention it when it's really tougher. Remember, don't be a coward.
The best way is to sit down and talk at the cold drink bar first. If you can solve the misunderstanding, you don't have to start work. Remember, we don't make trouble, but we are never afraid of things.