Baby birds that are in the "pin feather" stage are within a week or so of learning how to fly. I agree with Denyce that a rehabber should take over before something goes wrong. Different birds have VERY different nutritional requirements, and even though the food you gave them perked them up...it may not meet their needs. Some baby birds are strictly insectivores, others may be omnivores etc. One can often not tell, and better to be on the safe side and let someone who knows the species take over.