I'm glad your kitty is home. Sorry they put her on DM, unfortunately a lot of vets do that.
Your cat may not like the DM food, many don't. Most people here feed their cats low carb commercial wet food or raw food. Examples are Wellness, Fancy Feast Classic pate types. On the right hand column of the
CatInfo website there is a document listing commercial cat foods and their protein/fat/carbs. We feed low carb, which is less than 10% carbs. You'll note that most if not all of the veterinary specialty foods are inappropriate for diabetics. And they are more expensive. All dry foods are too high in carbs. Just take back the DM food and tell your vet your cat wouldn't eat it. What did your cat eat before?
If you don't have or can't get some low carb commercial wet food around tonight, there are a couple of tricks you can try until you get some. Add some warm water to the wet food, that will enhance the smell. If you have something like tuna bonita flakes, add some of those. Also try a bit of parmesan cheese sprinkled on top, or canned tuna water from (tuna packed in water only, nothing that has onions or soy). A lot of people use
Fortiflora, but that would have to wait for Amazon or can be purchased from the vet. I sometimes have to sprinkle freeze dried chicken breast pieces on one of my cat's food. They are great no carb treats and are common here for treats after blood testing. Just to get her to eat, even a boiled chicken breast will get something in her. Good luck!