Question - Way To Make Downloaded Sim Not an Occult?

Unfortunately, no, there is no way to turn an occult sim back to non-occult sim through CAS.

You have two ways here. I'd make a separate save to cure her and then do one of the following:

• Wolf-Be-Gone potion: This potion can be made to cure werewolves. You can either try to find it in the Gallery (though I don't know exactly if it'll be possible through there). Or, have another werewolf learn the Lunar Epiphany ability through reading werewolf books, then read more to learn the potion, then collect the required ingredients and make it through a bar. Then add her to the household (don't add her before, she may gain additional traits/skills/loot during that time) and have her drink it.
  
• Or... Cheats... Still...
  While she is selected, the cheats you must enter are these:
  

  testingcheats on

  
  And then:
  

  traits.remove_trait trait_OccultWerewolf

  
  And it'll remove the occult status. In addition, if you enable testing cheats in one save, it won't be enabled in other saves, thus this is why I suggested another save.

Whichever method (besides mods) you choose, good luck!