She is an indoor cat, but we have that little door thing that she can use to walk outside. So we feed her inside and she always goes outside and ignores the food we give her and she flies over to our backyard garden and eats stuff. And she usually will bring stuff from our garden and bring it to its nest. We give her this expensive brand called Cateata or somethin. She just likes to fly around in our yard and eat in her nest? Is this normal?

Are you sure your so called "cat" isn't a bird? Because what kind of cats have a nest and fly? And Cateata isn't a brand.

EASY 101 - take your bird to the pet shop and trade it for a real cat.

Your cat can probably smell all the dead animals and the chemicals in the canned food, and is probably getting better food from over the fence.
If she has free access to the outdoors, she is not an indoor cat.
Feed her only home cooked meals.

Can't find Cateata. Just because it's expensive doesn't mean it's good. Hard to say without seeing the ingredients. I would switched to a grain free canned diet and see if that entices her. Cats were made to eat meat, not little dehydrated bits of corn and chicken beak. If her food has corn, wheat, or by-products in, chances are she's finding something more like her natural diet outside.

First off this question is about a "Cat" not a "Bird". "Birds" fly. "Cats" don't. "Cats" don't have "nests". "Birds" have nests. You, my friend, seem to be a little confused. No such thing as Cateata.