help!!!

Hi All,
I have a large coop (about 1.2mtr sq) with a run just over 3.5mtr x 1 mtr. I have 2 partridge wyandtte bantams. all has been OK for about 6mths until a little while ago when 1 chook became broody. We do remove her from the coop most days and close up the pop hole (so she can't go back and brood). She is eating and drinking ok. My concern is the other one keeps pecking her around the back of the head - she's abit bald there now. it seems to be when then go to bed or when the weather is bad and they are sheltering from the rain. I use antipeck spray on her.
I don't want it to become a bigger problem than it already is so can anyone think of a way to get the dominant one to leave her alone. they have 'pay things' in the run which they like and also perches to sit on.

My other question is what to use in the coop for sleeping/nesting. I use wood shavings, is this OK? as I have heard that you shouldn't use it.
 

Thanks for the info about wood shavings.
Both my chooks are hens so you could be right there.
I silly question but whats a beak bit? I'm new to hen keeping -  you probably guessed that though!

thanks for all that. I'll have a look at them