I hope that you found her while you went out looking but it's more likely, being a cat, that she will return only when she feels like it. If you sit on your porch tonight, as Laura's Babies suggests, talking to her, tell her that trying to be as famous as Delta is just no joke and she's no Husky, able to brave the elements.

I feel sure that she will come home. If she isn't back tonight, you'll find her near the porch tomorrow morning looking at you as though you were supposed to keep the door open all night for her. I know the guilt is great but you can no more read a cat's mind completely than you can protect them from all ills. Many years ago, I had a cat called Sam who did the same thing to me. I was in absolute despair, visiting shelters, touring the neighborhood all night with a flashlight, etc. Two days later I saw him strolling through the garden towards the back deck as though nothing had happened.