Agreed with Red. Pink belly makes me think burn, not shedding.
If she likes to burrow down in the substrate there is a chance she could be burning her belly.
Sounds like you're doing a great job keeping her humidity levels perfect! I sometimes miss my BP's milky eye phase, especially Graeae my Ghost Pastel. She hides in her warm hide for a day or two before her shed and gets quite the attitude lol!!