I've had an subadult and an adult that got very orange on the belly and then it went away. I assumed it was due to shedding or newspaper. It stayed a while, then they went back to normal.

I would make certain she's not getting too humid or soaking a lot and causing some sort of irritation or fungus, and keep an eye on it. If she stays orange on the belly when she's an adult, you can always check if it's genetic with some breeding.