If it's their first clutch, as in agewise, there's not much to be worried about in my opinion, however, if the birds have been laying eggs prior to coming to you then I guess you have to find a proper breeding forum or a vet to search for an answer, as I myself am not a breeder (yet).
As for the chick with no feathers, they all hatched like this but within a couple of days fluffy whitish feathers appeared on their body and around 2 months of age they are covered with pin feathers all around the body. In the absence of a photo I can only guess that your baby is doing fine but I'm not sure since I haven't seen it.
It is advised to search for a breeders' forum (there may be some on the net).