Rooster and hens being mean to one chicken

I don't know what is going on but day before yesterday my dog attacked one of the hens. We got to her before anything serious happened. She was scared to death but other than that OK. Ever since that happened the other two hens and my rooster pecks at her and run her off if she gets too close. The three hens were always together, I called them the three stooges. I don't know why they are ignoring her. When they went to bed last night things were quiet. Will they come around??? Hope so. Thanks for any information on this..