I've raised several dogs over the past five years or so for a service dog organization, so can tell you a lot about the eating habits of dogs...
1. Don't feed your dog people food.
2. Dry kibble is enough. In general, it's best to find a dry food that has as few ingredients in it as possible. Many dogs get food allergies, just as people would if they ate the same thing every meal. By reducing the number of ingredients in the food you give them, you're more likely to get "whole" ingredients and the dog is less likely to have a bad reaction to it.
3. It is very common for dogs to all of a sudden stop liking the food they've been eating for a while. They get bored. It really is that simple. If you want to change it up a little bit, try just wetting the dry food a tiny bit. The water releases a bit of the smell of the food, so that might prompt the dog to dig in.
4. It's also possible the dog stopped eating when you left on your trip. That's very common. Some dogs get nervous when their people leave, so nervous they lose their appetite. Some dogs stop eating when their people leave as a form of manipulation, believe it or not. I've known a couple that will not travel until their cat dies because she won't eat whenever they leave her...she's holding them hostage!
If this was the reason she stopped eating, she'll start eating again!
5. Dogs will usually love whatever food you give them when it's brand new. At first, dogs love trying the new food...they're curious. Those sample sizes of food you get from the pet store or vet probably won't tell you whether the dog really will like the food long-term. You need to buy a whole bag and see if the dog will eat through that bag.
6. Don't leave the food out if she doesn't eat it. Then she won't eat during breakfast/dinner time. If she walks away from it, pick it up and try it again later, or just wait until her normal eating time. Once she's hungry, she'll eat.
7. Know that some dogs go through phases of being uninterested in food. Period. Usually this is in between growth spurts, but I had a dog that went from eating hardly anything to eating 9 cups of food per day in order to keep up with his growth and needed weight gain.
My (albeit non-medical) guess: your dog is fine, it's just picked a convenient time (for her) to throw a hissy fit about her food. If she is lethargic, drinking a ton of water, or throwing up, then she's sick. But if she's acting fine other than not eating, she's probably fine.
If she won't eat any more of her old food, go to the pet store and ask a clerk for advice on a food to try next (remember: less ingredients the better), maybe something similar to what she's been eating, but a little different. Then once you have the new food, mix half a serving of the new with half a serving of the old food, and do this for at least a few days. This will help prevent any stomach upset that sometimes comes from switching a dog's food suddenly.
Hope this helps! Good luck!