I agreed whole heartedly with the other posters who have advised you to ask that your pup remain with Mom until 12 weeks of age. I would insist actually, I have heard many stories of the difficulty owners have had due to early seperation. I always worry when I hear of a breeder offering pups to take home so early. I am actually wondering about the breeder. Did she mention a health guarentee? A guarentee of at least a year is important. Also did the breeder mention that you can take her into your vet for a health check? Its vital that you have time (usually 72 hours) to have your pup examined by your vet. In the event that the pup does not pass her health check you would be able to either select another pup or have your money refunded. If you have a contract I would look it over carefully and if there is no contract again a red flag would go up for me.
I am not really alarmed by her size, she isn't REALLY small--well for a 6 week old Yorkie lol. I hope that everything works out and that you soon are another lucky mom of a Yorkie
One more thing, her coloring looks great, Yorkies are black and tan but change as they mature. Chloe's coat has changed once and now at 3 her coat has changed again
So very glad that you are asking questions and doing your homework prior to bringing your little girl home. Welcome to YT!!