She looks like a healthy, happy ball to me.
Ball pythons are heavy bodied snakes, they are supposed to be round and plump, not stick thin like a cornsnake. Unfortunately, half-starved balls are the norm in petshops, most people don't know what a healthy ball is supposed to look like.
I've only see one truly FAT ball python. It was a photograph of a supposedly 5000 gram+ female, and she looked like she had swallowed a 2-liter soda bottle. She was FAT. Other than that one, I've seen the occasional pudgy one, but yours is neither.
Gale