The power play

Although, I hv 2 boys and a girl. The two boys are quite protective of her, they are the ones that can bully her. But, when the bigger one bullys her, the smaller boy would attack the big boy. And, when the 2 boys fight , girl will bunge in, to take away the bully's attention.
But, the 2boys are really afraid of the girl.
When she is well, they are restful.
When they are not behaving, the person to place the attention is the girl,  cause usually she can be the most naughty and intelligent among the boys.
So, if I hold on to her reins and manage her well.
The other 2 will follow automatically.