I have stray dog I named Tara

I kept seeing a strange dog in the neighborhood.  It would lay in my yard or the one across the street.  It went up and visited another dog too. It was so very scared. It kept it's tail down. I would feed it and yet it wouldn't allow me close and ran away if I tried to get close.  I was calling her the "community dog" before since no one claimed her.  The animal control people came out and put a big cage in the neighbor's yard  and then came and took it back a few days later.  I put her on Craig's List saying "is this your missing pet?"  I even had one person come to see if this was her dog and she said no.  Then I discovered my grandson with him. The tail would go up instead of down. I would have been scared to let them play together since one is so small and one is so big. Cody said it was ok. Then it allowed Cody to get close to it and it wanted to come inside. I told him it was ok. When it walked into my house I was sitting on the steps to go upstairs. This dog changed immediately. I was allowed to pet her. We had said "he" so long that it was hard to say "she" now.Cody said "sit" and she sit and he said "shake" and she lifted her paw to shake.  She has done the same for me.  I still plan to try to find the owner if it is a lost dog but maybe it was just dropped off and no one wanted her. Maybe she had been abused and that is why she was so scared at the beginning.This dog was amazing. Jamie came downstairs and she let him pet her. His friend was here and she let her pet her too.  I have never seen this happen before in my life.  I bought her a pink collar with reflectors on it and named her Taria.  She is learning her name. I don't even know if she has been spayed or might have a chip. I can't afford to go to the vet until next month. I want her checked real good and we have Value Vet that is less expensive. I wonder if the humane society would check her and tell me if she had it done or not. I was told they would do it cheaper then at a Vet's office if it needed to be done. They give rabies shots every year at schools for $10 - might be more now. Pets are expensive is another reason I didn't have one for over 14 years.  She is house broken, barks loud when someone comes to the door and plays with Oscar.  Today they both had hold on a toy and were pulling on it. Sometimes they drink out of the water bowl together at the same time.