Please Help!

I have recently became a new Finch owner and we now have 4 babies! Im really not sure what I can and cannot do with them. One of the babies just fell out of the nest and it seems like the proud parents are trying to get him back in. They arent eating own their own yet so Im wondering if this is the begining stages of this process. They have some color and I'm pretty sure they are about 3wks old. Any help would be greatly appreciated