Here's one more article:
Color Dilution Alopecia | Dermatology for Animals - Part 1
Definitely see a veterinary dermatologist to get an accurate diagnosis, because there are other things that can cause baldness in Yorkies that are more treatable, such as allergies, ringworm, etc.
If it does turn out to be CDA, don't worry too much, because your dog can still live a full, healthy life. You would just have to take extra steps to maintain her skin and keep her comfortable. Thanks for taking care of her!