Cochin's flying at younger chicks?

[peep peep]

I have 3 silkie chicks 2-3 weeks old, a cochin frizzle 3 weeks old, and another cochin frizzle 4 weeks old. They're in the same brooder box with no problems, except now the 4 week old frizzle is flying at the younger chicks aggressively. Could the little one's be harassing her? Does she need more space than the others? What could be the problem?

I don't want anyone to get hurt.

 

[cmfarm]

If it looks like it is hurting the younger ones I would seperate it from the rest.