Add lots of extra oxygen to the water..
Use some aquarium salt as a tonic, it will lower stress levels.
Cover the aquarium and remove any possible stresses.. no lights, etc..
Extra water changes, and make sure she keeps feeding. Use live foods if you have to.. Worms are always nutritious.
I would stay away from any other medications like aspirin, aloe, stress coat, or melafix. It might cause problems. I have succesfuly used Melafix on rays before, but not nearly a full dosage. Other reports have told me that Melafix can be detrimental to the rays..