Scale problem with ball python?

[VallenDark]

Hello!! I'm new to the forum. I joined particularly for this one question, because I'm worried about it and I don't know very many snake lovers other then my roommate. Since she doesn't know what's going on, here we are.

A little back story: I recently bought an albino ball python from a lady on Kijiji. The issue is, I think there was some issues with where she was living. First off, it was a tub with very little ventilation. Only a small area was cut out. Next... It was always really humid. I had her in there for two days yet I never once had to mist it. And.. we don't think her cage was ever cleaned properly. The woodchips/dirt mix was moldy in some places and it smelled. Also the only source of heat was a small heat pad taped to the bottom. And food: the lady only fed her minimumly due to her being a picky eater. One F/T ASF a week, at most. We're thinking she's around 3, so she should be eating more. My friends Ball Python eats two ASF when he's only 2. He's a lot thicker then her.

The issue: Some of her scales are red and lifted. Some spots look very soft and thin. There's also a lot of dry spots.

Question: What can the issue be, and how do I fix it?

About her living situation now: She's now in a new terrarium with a mesh top and well ventilated, and nice clean bedding. Heat is regulated, and she is regularly misted.