I am also intersted as to why you chose the Yorkie breed inparticular? What your goals are as a breeder, and if your aware that very tiny Yorkies can have more health problems?
AND if you have had enough experience with the breed or just intersted in making puppies to sell?
What would you do if the mother dog got into trouble during labor? The moms generally have small litters, and sometimes require have C-sections .It is an enormous responsibilty that should not be taken lightly for anyone, regardless of age.
I am thinking that once the novelty wears off that you will more interested in dating, and your education, rather then devoting ALL of your time with breeding.