Like others said if she has been kept this way for over a year temps might not be an issue. I would ask though, how you are measuring your temps. Depending on your thermostat and probe placement, the actual temps your snake is feeling could be slightly different.
I just have an Acu-rite thermometer from Walmart in with her. It has a probe on a wire for outdoor use. I place that on the hot side and the whole unit on the cool side.