The baby looking out of the frame on most of them kills them for me. Draws my eye right out of the photo. One thing, when shooting a subject against a wall/sheet/background/whatever, you should try to get them at least a few feet away from it. This will help to eliminate shadows on the background, and it will also give some seperation to the photo. As far as lighting goes, it's clearly on camera, or else way to close to the lens. You need to, at the very least, bounce it or diffuse it some. The best thing would be to get it off camera wirelessly, or with a ttl flash extension cord. Having the flash off camera allows greater depth and character to be added to the photo with lighting, and really makes for wayyy better portraits.