Like Kloey's mom said, breeding a PET is not the best of ideas...Did you buy your pup specifically for breeding from a breeder who knew that from the start? If so, you may just have a dog that would be a good breeder. If not, you have a long ways to go before making this decision. Here are some great threads to refer to:
http://www.yorkietalk.com/forums/showthread.php?t=34818 http://www.yorkietalk.com/forums/showthread.php?t=35559 http://www.yorkietalk.com/forums/showthread.php?t=35063
AND that is just a FEW! Go to search and type in "Breeding" and you have your homework right there.
If that is what you decide to do, so be it. I hope you and your family are prepared, your girl gets tested, and you find yourself a mentor. Good luck!