Pedialyte is to put electrolytes back in the system which are lost if a cat is dehydrated or has dire-rear.
The Nutrical is a vitamin paste and the Hill's A/D is a high calorie RX food.
If she is getting vitamins by other means, then Nutrical is not necessary.
By all means, follow your Vet's instructions. I am not a vet.

Get well soon, so you can shine again, Star.