Why doesn't my yorkshire terrier have any teeth yet?

My Yorkie is almost 8 weeks old, and still has not 1 tooth in her mouth. Is this normal ? I got her when she was 3 weeks old. Her mother died when giving birth. Should I just be patient ?

How is the Yorkies condition? Because this is not normal.
Now do not necessarily be alarmed yet, however do have her taken into a veterinary clinic.
Usually, dogs will be born with their baby teeth. Even those who do not show, should quickly break them in, similar to a child's. By eight weeks, you're puppy should be close to eating solids. If you are bottle feeding it, it may be that she is not getting the right nutrition.
Though, it takes about 6 months before the Baby teeth heed room for permanent ones.
This may have something to do with the nursing or formula you may be using, if you are.
Most importantly, I would suggest taking her to a vet for an evaluation, above all.