Hi There!
Was your Ball Python recently purchased?
If so have you ever examined her closely for ticks,sometimes ticks can cause infection at thier bite sites that turn into little sores.
You should examine the snake for the presence of ticks if she was recently purchased or has been around any other snakes.
Other things it could be are skin infections,somesnakes will get skin blisters if they soak in water too long or if thier cage conditions are overly humid,damp or dirty.
I can't really see these spots in the picture too well but those are the things that immediately come to mind,i have seen many infected sores caused by ticks,mostly in wild caught Ball Pythons but in "shared" ticks where they traveled from other snakes to Boas,etc...
These sores will also develop from improper or incomplete removal of ticks,either by being too aggressive and digging in deep into the skin when removing a tick or by leaving parts behind and failing to properly treat each removal site with antiseptic rinse.
Check your cage conditions,look closely for ticks and if the condition doesn't clear up or spreads then seek the attention of a Vet for your snake.
StormyHall