All the kibble foods you mentioned are good to feed. If she is really small, - the wee bits are great cause the pieces are very tiny. I would go with any of those. Know what I do when I get those samples? I put them in the treat/training bag and use them as that and my pups think they're getting a real treat.
Merricks is good and Solid Gold products I've heard that Chicken Soup is good but haven't used it myself.
good luck!