A lot of people stuff their babies with as much food as they'll take to get them up to size for breeding quickly. Personally I don't think that's good for the animal's long-term health, and people have reported fatty liver disease killing off their ball pythons at a young age. These guys are designed naturally to survive long periods with little or no food.
Others feed their snakes just barely enough to keep them alive. If the spine is prominent then they're too thin.
I would look at the pictures. As long as the snakes don't look underweight and the body condition is good, they're likely fine.