Don't worry. My Yorkie girls hair is the exact same as yours. Her coloring is a little different. She has very typical yorkie markings. Our pups have what is considered a "silky coat" it's straight, fine and shiny, which is exactly what they are supposed to have according to the AKC. It will grow in. Just takes more time than the wirey cottony coat. My girl is a 7th generation AKC pedigree. So I have no doubts
don't be discouraged. She's ADORABLE!