The Weruva pouches have a lot of liquid in them versus the cans. Your pet store should carry them. You can try the chicken with the pumpkin. Pumpkin has fiber which just helps with a healthy digestive system. Know that Weruva is not a cheap food by any means but the ingredients are great and like Brian said, it looks good enough for humans to eat. Other manufacturers make food in pouches, so you have a huge assortment to choose from. Just check the ingredients.
Hopefully a healthy cat will be hungry. However, not sure why your vet didn't mention cats can not go more than 48 hours without eating before fatty liver disease starts. The body starts pulling the fat from the liver to survive. When I took Raiden to an emergency vet after he hadn't eaten in 24 hours, I told the vet I was concerned about the fatty liver disease and he told me that many cat owners are not aware of it and by the time they bring their cat in, it's too late for the cat. And I would think a 2-1/2 pound kitten would be especially susceptible.
On your visit to the pet store, pick up a variety of foods-- one or two of each and try them out. I understand the changing of the diet thing but if you choose the foods with only the meat and broth and vitamins and supplements, there should not be a huge difference. Basically, you can chose from beef, chicken, turkey, lamb, rabbit, venison, duck, fish of some type-- and I might also suggest you buy a ceramic or stainless steel water fountain for your Trixie. My Raiden loves drinking from his.