Unless there is a problem, don't create one. If this little one is healthy, and happy, then treat her like a dog! She will be much happier and your life together will be much more pleasant. Have any and all testing done that will rule out liver shunt, and other common Yorkie ailments and then relax and enjoy your new baby. Don't focus on the "tiny" part.... focus on the "I love yorkies" part. She is a gift and is coming into your life for a purpose.