Is there any other fish in there that would make a snack out of them? If not, they'll be fine with the parents. I would continue to give them fry food yet for a couple more weeks, either the First Bites or finely crushed flakes. In my cory fry tank, the younger ones still sift through the moss and the prefilter for food and the older ones are out front taking pellets. A couple more weeks will make a big difference in their size and they will loose some of the instinct to hide for survival.