I rescued a baby back on July 5th. She was supposedly 6 months old but only weighed in at 44 grams. She was very skinny, very dehydrated, and had a back stuck shed with eye-caps. What I was advised to do was ignore the skin issues until she's back up to proper weight. Like others have said, make sure she's in the appropriate sized home with a hide (or two). Make sure the temps and humidity is spot on and feed her on a 5 day schedule (I started out with small meals for the first three or four feedings and then slowly worked up to an appropriate sized meal) until she looks fuller. Then deal with the shedding issue.
This was my girl when I first got her:
Here is her about a month later. I was working on getting her to gain weight. I hadn't dealt with the shed. You can CLEARLY see that she has an entire layer of skin all over her body. It was starting to flake around her belly.
And finally, here is her about two weeks ago. Since I rescued her, she's now at 100g (total gain of 60 grams in 2 months). I fixed her shedding issue and she has since shed on her own (perfectly, I might add!) She's still recovering but she's my best eater and most tolerant of my affections.
I hope your little girl will pull through just as my Fluffy did. Good luck! Keep us updated!