Woah, didn't know this had been commented on again.
Yes, my little roach is still fighting like the trooper it is, considering that all my other roaches died I shouldn't tempt fate, but I nicknamed it Panic.
It's growing extremely slowly, it's only on its fourth moult but it is active and healthy and eats and drinks regularly, and it does shed. To all intents and purposes it's a normal roach, just slowed down! I am hoping to wait until it's sub-adult/adult and then get some more to keep it company, but at the moment I don't want to risk other roaches injuring it until it's a bit bigger.
It just turned a year old, so you can see how wee it is compared to how big a normal hisser is at a year old. The best I can fathom is that because the mother died the litter were born weak or immunocompromised or in some way lacking, which was why there were only six in the litter, and why the other five died soon after. 'Panic' was simply the lucky one that was undamaged enough to survive, but was stunted or lacking in some way that slowed its growth down somewhat.