Welcome to YT. You will learn a great deal on this site regarding Yorkies.
First of all there is no such thing as a teacup yorkie. Please stay away from anyone who advertises them. A yorkie is a yorkie wether it be 1lb or 13lbs it is still a yorkie. The term teacup is used to jack up the prices on the little ones. Be carefull because the little ones can have many health problems. Sad but true. Any one who advertises teacup yorkies is looking at your wallet not the health of their yorkies.
Do some research on this site regarding it and you will learn all you need to know to get your baby.
Good luck.
Carol & Buddy
AKC weight for what is considered a standard yorkie it up to 7lbs.
Anything over can not be shown but is still considered a yorkie.