I agree that adding a humid hide might be a good idea. I don’t [mist] my enclosures but I will dump a bowl of water into the substrate if I think the ambient humidity is too low.
It's much harder to see an impending shed cycle on a white snake, so they're less "forgiving" if you don't increase their humidity to help their shed cycle. But you still have time to help- as suggested, a humid hide & increasing the humidity should help a lot.
Rudeness is the weak man's imitation of strength. Eric Hoffer(1902 - 1983)
“The greatness of a nation and its moral progress can be judged by the way its animals are treated.” ~ Gandhi