Ok, that is a bad burn and may be even recent. Does your friend have a thermostat regulating the under-tank heater? If not then that's the biggest problem that needs to be fixed. As you're about to find out a thermostat is a lot cheaper than a vet bill for a burned critter (I'd be looking at a $250 bill from my exotic specialist).
The snake needs to go into a tub on paper and kept very clean - no natural substrate.
Soaking in water with enough iodine/betadine added so it looks like weak tea is a good idea. You may have to support the snake's head if it's weak as you don't want it drinking the water.
I would write this girl off as a possible breeder with the burns around the vent area, there will be scarring and that could interfere with egg laying.
Also if you don't have money in savings or a line of credit to tap I would rethink breeding. When an emergency crops up your gravid snake will need a vet immediately, not next week when you get paid.