When we got her from the "breeder" she was on purina puppy chow.
So we switched her to blue buffalo small breed puppy food. 5 stars. And she has really been growing since we started feeding her that. When I got her at 2 months she was 1.8 pounds. Could feel her ribs and spine pretty well.
Now she is 3 pounds and no longer can feel the ribs and spine! She is 3 months as well!