I really do understand where your heart was at when you rescued the little guy, but I can also understand that Turtle and Duckie's owners will likely be upset since they've been counting on you to adopt their yorkies. I know that if it were me, I would be upset too.
I'm not trying to be mean at all, because I've acted with my heart more than once when I probably shouldn't have, but was it even a good idea to add the other little boy or Turtle and Duckie to your family if you are financially struggling? I have 4 and the bills for small things alone REALLY add up.
If something major happened I would have a very hard time getting them the care they need immediately. I know I might get comments for that, but it's true. I'm in no way financially prepared for a disaster if one was to occur with one of my babies let alone 4. I would get them the care they needed somehow, but it would likely put my under financially.
I know what's done is done, but what I would do is apologize to the family that you were supposed to be adoptiong from and understand they will be upset most likely. Take good care of your yorkies you have now and wait till you are in a better place before adding anymore.
That's just my .02
