ok, I've read all the comments. You live in the country and no doubt get strays. I live in the country and have a great dog Annie that was a stray. I made no effort whatsoever to find the owner. She looked so bad that I just kept her; that was six years ago.

IMO you've done enough to try to find the owner by leaving a message. I personally would not do flyers or call vets. Now it's waiting time. Just treat her the way she deserves and hopefully noone will call.