I have gotten to the point that I honestly feel that I am robbing my kitties of fresh air and the beauty of the outdoors
I feel that way sometimes too. I just open a window and let them sit in it. I'm sure Hallie Sue will come back. Make sure you check the perimeter of your property. She's gotta be around somewhere. And don't feel guilty. It's not your fault. You've heard about what curiosity did to the cat, haven't you??