If your dog is larger than your bitch, you really need to seriously consider Dizzy & Brainless's postings. When breeding Yorkies, the practise is to use a dog that's smaller than the bitch to prevent health problems, especially during delivery--blockage in the birth canal can happen when a puppy is too large.
Sure, she could easily have the puppies ...but do you want to take any chances with her life & health? Breeding is not as easy as many would like to think of it. Death & serious illness can occur, especially if the male is larger than your female.
I don't want to be an alarmist. I'm just mentioning the possibilities.
good luck
toodles