Hen gone broody?

I think that my light sussex has gone broody, she has stopped coming out of the hen house she is sitting on the floor wings slightly spred not eating or drinking, if you go near her she is making a high pitched shreek. Anyone with ideas as what to do?
Have lifted her out a couple of times and blocked the house up so she does ear a little when i have done this. Have also had a good look at her she seems ok other than finding mites (which i have dusted her for) the other two are not laying as normal but not sure if thats because she is putting them off with her noise.

 

Don't think can let her stay broody!Would love to get hold of firtilzed for her to sit on, had enough problem gettin rid of unwanted cock birds previously.  Am i doing the right  thing by not letting her sit all day in the coop? she is sitiing on her daily egg and crushing it then she has a realy messy belly that is hard as rock.

She is a big girl thats why not so worried about her not eating just yet!! Its a good job she is not doin the proper job as she would have no chicks left.