What Breed Is My Dog?

Her name is Angie. My friend gave her to me years ago as a gift. She told me that Angie is a mixed breed, but she wasn't sure what breed she is mixed with. I know she has Chihuahua, but the other half I don't know. She's bigger than a Chi and her tail is curled. One of her ears folds and the other is up. Her eyes are big and her bark is strong. Any clue?