[misslissa]

i'm really sorry this happened to Sophie but let me try to put this in a different light.
someone breaks in to your home while you are at work and steals Sophie thinking they will sell her or some such thing but when they see your fliers and posters all over town about her they feel its no longer worth it and they dump her she is picked up and taken to a shelter the shelter has a different microchip scanner and it will not read her chip being as she is a yorkie and they know they can adopt her they take her in to be spayed again but they see the blob and know what it means(because the rescue groups in your area will know) and dont put her through that again
from your pics Sophie seems tiny it seems to me that having major surgery again would be way worse for her then having a ugly black spot on her belly.