she never finish her food.

Don't feed your Dog the cheap stuff, all fillers and no quality meat. And yes, believe it or not, most dogs know the difference...I don't think it has to do with being spoiled. Why would you feed you Dog something you wouldn't eat.
I love Life Abuandance you can check it out here www.HealthyTownandCountryPets.com, get delivered right to your door. You also can find good quality foods in Natrual Pet Stores.
If a higher quality food doesn't work get your Dog checked out by a Vet.
Good Luck ;-)

What kind of dog is it? Some dogs don't like certain foods. Try getting her a recommended food for that specific breed. Maybe you just put to much food in the bowl. Maybe you have a spoiled dog and they want higher quality food. Maybe they have worms. There are a bunch of reasons why your dog isn't eating the food.