If those weights are accurate then you are right this snake has a problem. BPs go on hunger strikes, but they aren't supposed to lose more than 50% of their weight.

If she lost all that weight in the 2 weeks since the bad shed, then I'd recommend rushing her to the vet. I'd guess something pretty significant is wrong if the weight was lost that quickly. A hunger strike alone would not cause a sudden drop like that.

You also need to go over your husbandry carefully. A young BP shouldn't go on a hunger strike, so often it means something isn't right in their environment.