Pekingese inbreeding?

All purebred dogs are inbred. What your dogs did was called line-breeding and is used by many breeders to get certain characteristics in their dogs. If your dogs are AKC registered and you can get a look far enough back in their pedigree, or if you look up how the Pekingese breed was founded, you can see where they were all inbred. The puppies, if there are any, should be fine.