I'm sorry you haven't been able to get her. Have you seen evidence of her?? Maybe she has found a secure spot to roost at night, if you ever do get her back she will have some good 'street smarts'!
Maybe try putting a bowl of feed out near where you last saw her. Keep putting food out for a week or so and if she has found it, she will realize it's an easy source of food rather than foraging. After a while, gradually move the food closer to the coop. If you have places that are under cover...