Prazi = Internal parasite medication.
If shes ever been fed live she may have them. If she does have them she may not show any signs, and they may not have any ill effects at this time, but they are added stress, this in combination with other mildly stressfull things such as poor water quality are a perfect recipe for potential disaster long term such as a shortened overall lifespan.
I'm no expert on keeping rays but I have had a lot of them and have had them for a while, I've had more then my fair share of problems with them. IF that ray was in my tank I would be taking action. Like I said the tail appearence would lead me to believe she needs a little TLC.
Not telling you how to raise your ray, but rather offering advice that may yield an improvement in the health of your ray.
Ghost shrimp are very expensive in terms of the amount of nutrition they offer your ray. Good for sick or freshly imported rays to entice them to eat but I wouldn't view them as part of a regular diet just cuase of the cost factor. Nightcrawlers are good for beefing them up but the must be offered frequently. My lil pup that's just a couple months old will eat 3-4 crawlers a day, but they must be offered 2-3 times a day.