Lilith seems to be getting better, but she's still not 100%
I've been bathing her tail in warm water, and that seems to have stopped the angry looking redness. She doesn't pull away as much if it's touched and her scales aren't as soft. Also, there is no more fluid coming out from under her scale.
Today I was able to buy 'Zoo Med Wound Healing Aid' for cuts, infections, burns etc online and hopefully it'll be here soon so I can get her back to normal and with her sister Ruby ^^
As for the heating problem, untill I have the money for a thermostat the heatmat is fixed to the wall to provide her with enough heat to not become even more sick.
Good to hear progress has been made on the tail but mats are contact heaters mainly, on the wall they are not doing anything for a snake at ground level.