She's still quite young and she could be really stressed, but yeah - you've got to get some food in her. You might try some cracker to settle tummy (or bread) - sometimes that stims the appetite. Also, try some peanut butter (dense in calories), bits of cheese (but not too much). Sprinkle parmesan on her dog food. A bit of cottage cheese.
If it goes on, she may need to go to the vet for IV, which you hate to do. And if it goes on a long time, you'd need to consider a liver problem.
Try not to worry though, it is probably just transition stress. You are mixing canned w/ kibble right? Canned is usually more smelly and appetizing.
