That setup looks OK, I'd switch out the sand for coconut husk substrate like Ecoearth or Reptichip and keep it moist but not soaking wet. You'll need a under tank heat mat with a thermostat set to 88F. She should also be offered small rats once a week, she does look very skinny, should be eating weekly until she gets her shape back. I'd say get some rats just smaller than the width of her widest spot to start. You can do frozen thawed, just make sure they are thawed all the way through and warmed to about 110F before you feed. Or you can do fresh killed using CO2, which I like the best. I prefer not to feed live, but you can in a pinch if you need to. Or you can do 3-4 adult mice about 10 minutes apart.
I can't believe she is 8 years old, my snakes are that big at about one year old. She should be triple that size. I'd feed every 4-7 days for a full year, then once she is on bigger rats cut back to 7-10 days.