I was out in my yard at about 6pm and all 4 of my chickens were in their pen.
Went out about 7:45 and only 3 chickens there.
Looked around and no sign of her. No feathers or anything out of the ordinary in or around the pen, chickens don't just run away... do they?
My only thought would be a hawk but I am down 1 chicken and have only had them 17 days.