I don't think she is very far away. Keep food out for her, go out and sit in your yard and talk to her at night when she is normally active. (Isn't that how Lisa got Pete back when he came up missing?). Don't give up looking, she probably isn't very far away.

When Klinger ran off, he was at a neighbors, laying in the yard. Mike saw him and walked into the yard and asked the lady of that was her cat and she lied and said it was. He was RIGHT there where he heard us calling out to him day after day and night after night and he didn't even pick his head up to look. If it hadn't been for Patty just walking into the ladys yard and snatching him up, we wouldn't have gotten him back. POINT IS.... she probably is with in calling distance and hears you calling..