At this point, personally I would try something different. How about eliminating factors?
If you are doing a lot of waterchanges... stop. Watch the animal - and let that guide for doing them. If it doesn't get worse, don't do one. There could be something in your water impacting her that you just don't see. Could be preventing the cycle from happening correctly. Slowly add salt to keep that level coming up. It will help ease the stress on the ray. Get it up to 1.010, then to .015 the next day, then .020 and so on. keep it at .025 in the long run.
Do a once a day feeding (a light feeding) to help prevent excess ammonia building up.