Chis are so weird.
I agree with the mixing wet food in idea... I put about a tablespoon of canned Wellness in with Cooper's dinner (I don't free feed) every night. He loves it. It's just enough to make it "worth" eating dinner to him. LOL
You might also want to try putting a little chicken broth/stock on the food, just enough to moisten it slightly... that way, the smell will attract the dog.
Bad auntie... spoiling your chi like that. She should be ashamed.