Baby hissers look pretty much like little adults within a few hours of birth, and they are fairly good sized.
Here is a picture of a mother and her just delivered litter to show the size reference.
The babies do not hang out with the parents. They are around the female for a short while, but then disperse.
Since babies are pretty obvious I'm going to venture that your hissers have mites. This may not be the case, but mites are common in roach colonies.
As I understand it, they are not a mite species that will threaten your reptiles, they are host specific. Regardless, they will multiply and should be eliminated if possible.
With only 5 roaches, it shouldn't be a problem. Just keep them well cleaned.
I have been told of one method to remove mites which is to shake the roach in a zip lock bag containing flour. The mites will remain in the flour and you mist the roach with plain water once you're finished to clean the flour off them.
Clean the cage at the same time to remove any strays and/or eggs in the cage.
A repeat treatment or two may be needed to completely eliminate them.