your snake was off feed for 1.5 months, then you gave it a large meal. 1.5 months isn't a long time for your snake to be off feed. but you should ease your snake back to feeding not slam it. I would wait the 2 weeks for her digestive track to settle down, then offer her one mouse not four, wait one week or less if it poops. feed her again, once she goes then start increasing the amount. many things can cause a regurg, I would try this and if it regurg again then take it to the vet.

one more thing, you can't go by the temp that's display on your thermostat. you need a way to check the temps of your tubs. I use a temp gun.