akc300, don't be fooled by people who know nothing about this breed and don't be fooled by unscrupulous breeders. There is no such thing as a teacup yorkie....There is only ONE kind of yorkie...Yes, some are smaller and yes, some are larger, but they are ALL yorkies
The AKC only recognizes yorkies as being toy dogs. Do a search on here, and you will get lots of info on the topic
I hope your friend's mom really learns to love this furbaby regardless of it's size. Believe me, instead of focusing on size, they should be focused on whether or not this yorkie is healthy. A standard yorkie is 7lbs or under, but even if the furbaby gets to be 10 lbs, he will still be a very small dog.