She is still doing great! She doesn't seem to be in any pain or anything. She was playing like crazy this morning, running around like a goof ball playing with a toy. It seems to me she is not in and out of the cat box as much as she was, so hopefully she is getting better!
She goes in on the 13th for a check-up and they will do a urinalysis to see if the antibiotics are getting rid of the infection, etc. But no x-rays until the end of June to see if it has gone away.
I will definitely be switching my kitty to the prescription food permanently to avoid this issue again. I can't imagine switching one cat, and not switching the other. So I am going to ask the vet if it is okay for them both to be on the prescription food. I imagine it would be fine for the other kitty too, help avoid this ever being an issue for her too.