Welcome to Yorkie Talk. It's very common for Yorkies to have these kind of coat variations. The ideal Yorkie coat is one of the hardest to achieve in dog breeding.
Your girl may have a combo coat, part silk and part soft/cotton coat. Curls near the rump are very common. It could be that the curls are from something as simple as not drying that area as thoroughly as the front after a bath.
My younger boy tends to sit while I dry his hair and ends up with a somewhat curly look on his hind quarters. Usually the hair straightens once it is completely dry and combed out.
__________________ Kristin, Max and Teddy
|