I've just been looking on the net and there was an obscure series called "Little Muppet Monsters" but thats the only other baby muppet show and that had 18 episodes made and only 2 aired because it was so bad. AFAIK Fraggle babies didn't appear in Muppet Babies.

Just to whet the appitite go here for the US intro to Fraggle Rock (notice theres no lighthouse its Sprocket with an old geezer in a shed).