I'm rather leaning toward this assessment as well. This snake is very round and has obvious fat rolls. The head is tiny compared the rest of her body and her spine looks sunken. You have a fat snake.
The volta ball pythons don't just weigh a lot, they're proportionately larger. If you look at some videos of specimens in people's collections when they're in the same frame as the person you will see the snake is quite large. It's especially noticeable if you compare the head to that of a normal ball python.