I wouldn't give up on finding her owners yet. She could have been stolen and escaped, her family may have left her with dog sitters and still be out of town, and not even know she's missing. Someone could have found her in another state or county and driven her home only to lose her in a totally foreign area and her family would never know to look there. Have you contacted breed rescue to see if they have any lost dog reports that match her description? As someone who has a lost chipped dog still out there somewhere, I would hope that anyone thinking of keeping a found dog do their utmost to find their family. I mean, I hope Anko is safe and with a loving family vs. dead or stray, but at the same time it breaks my heart that she isn't with me.