Thank you for saving the little ones! My husband and I have only ever rescued our babies. Our first Yorkie was in 2009 and she passed away tragically in 2013. She was 9 years old. We adopted our second Yorkie shortly thereafter. We've always had Chihuahuas, so those were our first Yorkies and we immediately fell in love with the breed.
They've all varied in size, but our Yorkie is 4.5 lbs. And our newest addition, Pinky (a Chi), is 3.5 lbs. - before we adopted her, her weight was not noted so we had no idea how tiny she was until we met her in person. Anyway, their size is just a number and its amazing how well they fit in and how active they are. It just takes the rescues a little longer to really warm up, but once they do there is nothing like them!
After going through so many varieties of food, we've finally settled with Castor and Pollux Organix for small breeds. Its fantastic. And our Yorkie (who is the pickiest) loves it! We're very strict with not allowing them table scraps or human food because many years ago our first Chihuahua got deathly ill from eating meats (hotdogs, bacon, steak, hamburger - even though none had seasoning, it was really awful that we fed her that) on a regular basis (we honestly were unaware of the harm it does to their little intestines). So now we try to stick with organic dry kibble, which is much much better for them.
Best wishes for you and your new babies!