I was told Chow mix. She is 4 years old. I've never owned or personally met anything Chow/Chow mixed. She has blue spots on her tongue

She is 21" tall and has a 18" neck. A little bit thin right now (Should fatten right up now that shes here!) Any guess what she is mixed with?
Also, I looked up chows and I knew they were known for the blue tongue however I did not know about the strait back legs. As you can see in her pictures her back legs are different, is this the normal or a "flaw" she looks a little overly strait to me but then, I don't know much about that breed! I thought she had some pretty goofy back legs until we got home and looked up the breed, Now I'm not sure if its the breed or if its a flaw.