One of our is being bullied by the other chickens, too. I just keep her away from the others by putting her away from them and sometimes watching over her. If the others are bulling her, just stop them so that they know that it's wrong.
I'm not sure how sure situation will work out, or if they...
It sounds to me you've got the pecking order figured out! They will do this all the time, it's a line of order! Quail 3 is the 'big mamma' and is at the top of the pecking order. It would be a problem only if she were seeking out a bird and nonstop pecking her, otherwise this is normal.