Well,mine usually end up getting freaked out at night,it's long story,but they don't have a proper coop,but when it happens at night,if I don't find them,they sometimes don't show up till as late as 11 am.but for mine once I pick them up they almost always snap right out of it.I'm very worried...
Is there a dog that could be frightening her? I know that my chickens,when attacked run a far way,and freeze stiff,then hide in tall grass,looking like,well,a limp chicken