Shes by herself in a two gallon tank changes twice a week, 78 degrees and feeding her once daily 2-3 pellets. And she has a next door neighbor daniel who she seems to like, he never flares and she has gotten beeding stripes a couple of times.
Don't use salt for more than ten days. If the tap water is stressing her, it may be something in the water. You're water changes sound fine, so long as they are 100%. Does she have a filter? The current may cause her to be stressed out, but in the cave there is no current.
Try and get her lots of plants and decor to hide in if she might be shy :3 Fill that sucker with plants that are soft and billowy to hide behind and dart from one to another with. Perhaps offer another kind of cave, or remove the cave for a bit? If she wigs out, return it, but maybe she'll chill after a day or two.