Do what the above poster did, go to the respective websites for nutro, canidae, chicken soup, and any other names you have heard as good food and do a search. You may find a feed store close by that sells at least some of those brands, or who will order it for you. Really, nothing you can give as a supplement will make up for the amount of fillers in puppy chow/dog chow. It amounts to a whole lot of poop and not a lot of nutrition, which is probably why your girl is a little too thin, not drastic for a boxer puppy, just a tad, you just don't want it to ge to be any more. If you can't find anything, try adding a raw egg, cottage cheese, tuna fish, etc, to her kibble to help with the nutritional value.