I don't really know about it that well, but my best friend has two yorkies and one of them was a white puppy, and she was white for a while, but now she has a strawberry blond head and paws, and a grayish-white body. She turned out to be beautiful. If you aren't positively sure that the parents are your puppy's, and she stays white her whole live, she might be a westie. So, either way you are going to have a great friend for life.